I have configured external editors for specific file types. Works great!
Occasionally, I want to use the internal editor, temporarily, for a small number of files.
It's much faster using the internal editor than launching my entire development environment.
I would love a keyboard shortcut to once-off edit the current file(s) with the internal editor.
eg.
shift + enter = internal editor
shift + double click = internal editor
enter = external editor
double click = external editor
Or F3, borrowing from Total Commander's Lister.