I am implementing a global navigation solution.
The issue is this; long story short (I can elaborate on it if you wish): All pages in the _layouts directory override all the content in the "PlaceHolderTopNavBar" ContentPlaceHolder control in the MasterPage with a TopNavBar.ascx UserControl.
If you've created a custom MasterPage, and have also created your own custom navigation (perhaps with your own SiteMapProvider), these navigation customizations are not shown in any of the _layouts pages (such as Site Settings), because of the aforementioned issue.
The only way around this that I could find, is to edit the TopNavBar.ascx file directly. And even though I can create a solution that deploys fine, I still don't like that I have to overwrite a SharePoint file.
I would much rather be able to create an item in my Elements.xml file that overrides the ASPMenu control in the TopNavBar.ascx file, but I can't because it's not wrapped in a delegate.
Am I stuck with the wonky overwrite of the TopNavBar.ascx?
UPDATE: A better alternative that I have come up with so far, is to move the PlaceHolderTopNavBar ContentPlaceHolder control into a hidden div in the MasterPage while keeping their contents (the ASPMenu and SiteMapDataSource controls) where they are. Thus, they don't get replaced by the settings.aspx page.