diff --git a/middleman-core/fixtures/frontmatter-neighbor-app/config.rb b/middleman-core/fixtures/frontmatter-neighbor-app/config.rb
index e69de29b..50a368eb 100644
--- a/middleman-core/fixtures/frontmatter-neighbor-app/config.rb
+++ b/middleman-core/fixtures/frontmatter-neighbor-app/config.rb
@@ -0,0 +1,27 @@
+ignore '*.frontmatter'
+
+# Reads neighbor for every file on every refresh.
+# TODO: Optimize
+class NeighborFrontmatter < ::Middleman::Extension
+  self.resource_list_manipulator_priority = 81
+
+  def manipulate_resource_list(resources)
+    resources.each do |resource|
+      next unless resource.source_file
+
+      neighbor = "#{resource.source_file}.frontmatter"
+      if File.exists?(neighbor)
+        fmdata = app.extensions[:front_matter].frontmatter_and_content(neighbor).first
+        opts = fmdata.extract!(:layout, :layout_engine, :renderer_options, :directory_index, :content_type)
+        opts[:renderer_options].symbolize_keys! if opts.key?(:renderer_options)
+        ignored = fmdata.delete(:ignored)
+        resource.add_metadata options: opts, page: fmdata
+        resource.ignore! if ignored == true && !resource.is_a?(::Middleman::Sitemap::ProxyResource)
+      end
+    end
+  end
+end
+
+Middleman::Extensions.register :neighbor_frontmatter, NeighborFrontmatter unless Middleman::Extensions.registered.include? :neighbor_frontmatter
+
+activate :neighbor_frontmatter
diff --git a/middleman-core/fixtures/frontmatter-settings-neighbor-app/config.rb b/middleman-core/fixtures/frontmatter-settings-neighbor-app/config.rb
index a5e8129a..600b96f8 100644
--- a/middleman-core/fixtures/frontmatter-settings-neighbor-app/config.rb
+++ b/middleman-core/fixtures/frontmatter-settings-neighbor-app/config.rb
@@ -2,3 +2,31 @@
 proxy 'proxied.html', 'ignored.html'
 page 'override_layout.html', layout: :alternate
 page 'page_mentioned.html'
+
+ignore '*.frontmatter'
+
+# Reads neighbor for every file on every refresh.
+# TODO: Optimize
+class NeighborFrontmatter < ::Middleman::Extension
+  self.resource_list_manipulator_priority = 81
+
+  def manipulate_resource_list(resources)
+    resources.each do |resource|
+      next unless resource.source_file
+
+      neighbor = "#{resource.source_file}.frontmatter"
+      if File.exists?(neighbor)
+        fmdata = app.extensions[:front_matter].frontmatter_and_content(neighbor).first
+        opts = fmdata.extract!(:layout, :layout_engine, :renderer_options, :directory_index, :content_type)
+        opts[:renderer_options].symbolize_keys! if opts.key?(:renderer_options)
+        ignored = fmdata.delete(:ignored)
+        resource.add_metadata options: opts, page: fmdata
+        resource.ignore! if ignored == true && !resource.is_a?(::Middleman::Sitemap::ProxyResource)
+      end
+    end
+  end
+end
+
+Middleman::Extensions.register :neighbor_frontmatter, NeighborFrontmatter unless Middleman::Extensions.registered.include? :neighbor_frontmatter
+
+activate :neighbor_frontmatter
diff --git a/middleman-core/lib/middleman-core/core_extensions/front_matter.rb b/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
index 712d5d6c..72412398 100644
--- a/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
@@ -57,10 +57,6 @@ module Middleman::CoreExtensions
       end
     end
 
-    def after_configuration
-      app.ignore %r{\.frontmatter$}
-    end
-
     # Get the template data from a path
     # @param [String] path
     # @return [String]
@@ -70,16 +66,7 @@ module Middleman::CoreExtensions
 
     def data(path)
       p = normalize_path(path)
-      @cache[p] ||= begin
-        data, content = frontmatter_and_content(p)
-
-        if file_watcher.exists?("#{path}.frontmatter")
-          external_data, _ = frontmatter_and_content("#{p}.frontmatter")
-          data = external_data.deep_merge(data)
-        end
-
-        [data, content]
-      end
+      @cache[p] ||= frontmatter_and_content(p)
     end
 
     def clear_data(file)
@@ -88,11 +75,43 @@ module Middleman::CoreExtensions
       file = File.join(app.root, file)
       prefix = app.source_dir.sub(/\/$/, '') + '/'
       return unless file.include?(prefix)
-      path = file.sub(prefix, '').sub(/\.frontmatter$/, '')
+      path = file.sub(prefix, '')
 
       @cache.delete(path)
     end
 
+    # Get the frontmatter and plain content from a file
+    # @param [String] path
+    # @return [Array<Middleman::Util::HashWithIndifferentAccess, String>]
+    def frontmatter_and_content(path)
+      full_path = if Pathname(path).relative?
+        File.join(app.source_dir, path)
+      else
+        path
+      end
+
+      data = {}
+
+      return [data, nil] if !file_watcher.exists?(full_path) || ::Middleman::Util.binary?(full_path)
+
+      content = File.read(full_path)
+
+      begin
+        if content =~ /\A.*coding:/
+          lines = content.split(/\n/)
+          lines.shift
+          content = lines.join("\n")
+        end
+
+        result = parse_yaml_front_matter(content, full_path) || parse_json_front_matter(content, full_path)
+        return result if result
+      rescue
+        # Probably a binary file, move on
+      end
+
+      [data, content]
+    end
+
     private
 
     # Parse YAML frontmatter out of a string
@@ -142,38 +161,6 @@ module Middleman::CoreExtensions
       [{}, content]
     end
 
-    # Get the frontmatter and plain content from a file
-    # @param [String] path
-    # @return [Array<Middleman::Util::HashWithIndifferentAccess, String>]
-    def frontmatter_and_content(path)
-      full_path = if Pathname(path).relative?
-        File.join(app.source_dir, path)
-      else
-        path
-      end
-
-      data = {}
-
-      return [data, nil] if !file_watcher.exists?(full_path) || ::Middleman::Util.binary?(full_path)
-
-      content = File.read(full_path)
-
-      begin
-        if content =~ /\A.*coding:/
-          lines = content.split(/\n/)
-          lines.shift
-          content = lines.join("\n")
-        end
-
-        result = parse_yaml_front_matter(content, full_path) || parse_json_front_matter(content, full_path)
-        return result if result
-      rescue
-        # Probably a binary file, move on
-      end
-
-      [data, content]
-    end
-
     def normalize_path(path)
       path.sub(%r{^#{Regexp.escape(app.source_dir)}\/}, '')
     end
diff --git a/middleman-core/lib/middleman-core/core_extensions/routing.rb b/middleman-core/lib/middleman-core/core_extensions/routing.rb
index b7f4ee52..24539ce0 100644
--- a/middleman-core/lib/middleman-core/core_extensions/routing.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/routing.rb
@@ -45,8 +45,6 @@ module Middleman
         options = opts.dup
 
         # Default layout
-        # TODO: This seems wrong
-        options[:layout] = @app.config[:layout] if options[:layout].nil?
         metadata = {
           options: options,
           locals: options.delete(:locals) || {},
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/content_type.rb b/middleman-core/lib/middleman-core/sitemap/extensions/content_type.rb
deleted file mode 100644
index 23325012..00000000
--- a/middleman-core/lib/middleman-core/sitemap/extensions/content_type.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-require 'rack'
-
-module Middleman::Sitemap::Extensions
-  # Content type is implemented as a module so it can be overridden by other sitemap extensions
-  module ContentType
-    # The preferred MIME content type for this resource
-    def content_type
-      # Allow explcitly setting content type from page/proxy options or frontmatter
-      meta_type = options[:content_type]
-      return meta_type if meta_type
-
-      # Look up mime type based on extension
-      ::Rack::Mime.mime_type(ext, nil)
-    end
-  end
-end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb b/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
index 9ca344a2..b77f0e19 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/ignores.rb
@@ -12,7 +12,6 @@ module Middleman
           @ignored_callbacks = []
 
           sitemap.define_singleton_method :ignored?, &method(:ignored?)
-          ::Middleman::Sitemap::Resource.send :include, IgnoreResourceInstanceMethods
         end
 
         # Ignore a path or add an ignore callback
@@ -45,27 +44,6 @@ module Middleman
           @ignored_callbacks.any? { |b| b.call(path_clean) }
         end
       end
-
-      # Helpers methods for Resources
-      module IgnoreResourceInstanceMethods
-        # Ignore a resource directly, without going through the whole
-        # ignore filter stuff.
-        def ignore!
-          @ignored = true
-        end
-
-        # Whether the Resource is ignored
-        # @return [Boolean]
-        def ignored?
-          return true if @ignored
-
-          # Ignore based on the source path (without template extensions)
-          return true if @app.sitemap.ignored?(path)
-
-          # This allows files to be ignored by their source file name (with template extensions)
-          @app.sitemap.ignored?(source_file.sub("#{@app.source_dir}/", ''))
-        end
-      end
     end
   end
 end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb b/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
index b9abe44e..9acce571 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/proxies.rb
@@ -119,8 +119,7 @@ module Middleman
         resource
       end
 
-      # rubocop:disable AccessorMethodName
-      def get_source_file
+      def source_file
         target_resource.source_file
       end
 
@@ -130,17 +129,6 @@ module Middleman
 
         target_resource.content_type
       end
-
-      # Whether the Resource is ignored
-      # @return [Boolean]
-      def ignored?
-        return true if @ignored
-
-        # Ignore based on the source path (without template extensions)
-        return true if @app.sitemap.ignored?(path)
-
-        false
-      end
     end
   end
 end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb b/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
index 3f4dafd1..d6b79045 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/redirects.rb
@@ -75,18 +75,9 @@ module Middleman
           end
         end
 
-        def binary?
-          false
-        end
-
         def ignored?
           false
         end
-
-        # rubocop:disable AccessorMethodName
-        def get_source_file
-          ''
-        end
       end
     end
   end
diff --git a/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb b/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
index 4f5a646e..8d555fa6 100644
--- a/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
+++ b/middleman-core/lib/middleman-core/sitemap/extensions/request_endpoints.rb
@@ -64,18 +64,9 @@ module Middleman
           return output.call if output
         end
 
-        def binary?
-          false
-        end
-
         def ignored?
           false
         end
-
-        # rubocop:disable AccessorMethodName
-        def get_source_file
-          ''
-        end
       end
     end
   end
diff --git a/middleman-core/lib/middleman-core/sitemap/resource.rb b/middleman-core/lib/middleman-core/sitemap/resource.rb
index 97b4e832..fdd57b00 100644
--- a/middleman-core/lib/middleman-core/sitemap/resource.rb
+++ b/middleman-core/lib/middleman-core/sitemap/resource.rb
@@ -1,5 +1,5 @@
+require 'rack/mime'
 require 'middleman-core/sitemap/extensions/traversal'
-require 'middleman-core/sitemap/extensions/content_type'
 require 'middleman-core/file_renderer'
 require 'middleman-core/template_renderer'
 
@@ -9,7 +9,6 @@ module Middleman
     # Sitemap Resource class
     class Resource
       include Middleman::Sitemap::Extensions::Traversal
-      include Middleman::Sitemap::Extensions::ContentType
 
       # The source path of this resource (relative to the source directory,
       # without template extensions)
@@ -20,6 +19,10 @@ module Middleman
       # @return [String]
       attr_accessor :destination_path
 
+      # The on-disk source file for this resource, if there is one
+      # @return [String]
+      attr_reader :source_file
+
       # The path to use when requesting this resource. Normally it's
       # the same as {#destination_path} but it can be overridden in subclasses.
       # @return [String]
@@ -43,13 +46,6 @@ module Middleman
         @metadata = { options: {}, locals: {}, page: {} }
       end
 
-      # Set the on-disk source file for this resource
-      # @return [String]
-      def source_file
-        # TODO: Make this work when get_source_file doesn't exist
-        @source_file || get_source_file
-      end
-
       # Whether this resource has a template file
       # @return [Boolean]
       def template?
@@ -136,7 +132,30 @@ module Middleman
       #
       # @return [Boolean]
       def binary?
-        ::Middleman::Util.binary?(source_file)
+        source_file && ::Middleman::Util.binary?(source_file)
+      end
+
+      # Ignore a resource directly, without going through the whole
+      # ignore filter stuff.
+      # @return [void]
+      def ignore!
+        @ignored = true
+      end
+
+      # Whether the Resource is ignored
+      # @return [Boolean]
+      def ignored?
+        return true if @ignored
+        # Ignore based on the source path (without template extensions)
+        return true if @app.sitemap.ignored?(path)
+        # This allows files to be ignored by their source file name (with template extensions)
+        !self.is_a?(ProxyResource) && @app.sitemap.ignored?(source_file.sub("#{@app.source_dir}/", ''))
+      end
+
+      # The preferred MIME content type for this resource based on extension or metadata
+      # @return [String] MIME type for this resource
+      def content_type
+        options[:content_type] || ::Rack::Mime.mime_type(ext, nil)
       end
     end
   end