meanwhile, just today I went M-t between 'two words' in an email draft, and got words' 'two. woopsie ;-)
wasn't lisp supposed to be AI? :-)
Hunh. What version of Emacs was this in? I did M-t between 'two words' just now in 28.0.50 and got 'words two' as expected (but I think it's been working that way for a long time, at least that's how I remember it -- I wasn't surprised when The Right Thing happened).