> M-RET M-<right>

Appreciate the reply, but that's worse than what I was doing. M-<right>
is not anywhere close to my high frequency areas of finger activity.
I've changed all such keybindings.

I notice that C-M-RET is undefined. If anyone wants to add the
functionality as described in my original post, and bind it to that key
chord, I would be grateful; in the meantime, I'll create a macro /
interactive defun to do the same.