Cutting tile trim into internal corner

[Dumbo]

I used some Schlüter brushed metal box trims on a bathroom a few years ago.
Some of the external corners were rather exposed, and not wanting to risk a sharp edge injuring someone I used plug in external edges.......just seemed logical to use the internal plug in's as well.
The Schlüter corners looked well suited and a good fit.(Not all brands are)

Actually contrary to my earlier post I have used box trim ext corners .