A single type could be spread over multiple source files, but Roslyn currently only supports navigating to one initially. Subsequent navigations correctly bring up the Find References window and allow the user to select .

Right now you can workaround this limitation by executing a GTD on a type symbol, for example, and then F12ing again on the type symbol once you have been navigated.

When a source link file is opened from the Find References window in this way, and presumably once the multiple results work up front, the tab for the document is not correct, and the tab is not opened as readonly.