Bill Tindall, E.Tn.
"Since then I have coped the corners as Bill describes, rather than just mitering them as above. Having said that, the mitres have remained tight over the years."

I mitered the 1/4 round on M&T doors until recently. Like you, I have a dozen or more doors and side panels for chests done this way and none of the miters have opened in decades.

The miters are more fiddly to get perfect. The cope is more fun to make.