we hand craft all of our .axml Layouts in plain XML. Unfortunately it seems to be impossible to disable the Xamarin Android Designer in Visual Studio. Even when right-clicking a .axml file and choosing "Open With" and "XML (Text) Editor" (or "Source Code (Text) Editor"), the Xamarin Android Designer is opened. Also, trying to associate the "XML (Text) Editor" with the file extension .axml in the Visual Studio Options does not work. No matter what I try, .axml files are always opened in the Xamarin Android Designer. I assume that this is a bug in the Xamarin Visual Studio extension.
The problem we have with the Xamarin Android Designer is that opening a .axml file with it is very very slow. Also, the designer completely fails on all our manually built .axml files anyway.
I know that changing the file suffix to .xml would solve the problem. Unfortunately we have literally hundreds of .axml layout files and changing the file suffix on all of them is just no option.