As a programmer: I have two XDRs; both spend most of their time in portrait. Study after study has directly linked programmers' productivity to the amount of source-code they can simultaneously fit on-screen; and (modulo font-size, text columns, etceteras), portrait displays often fit more code from the same file(s).
Relatedly: It helps if you have a dual-level desk, where the front / keyboard portion can be adjusted to be higher than the rear / display portion:
View attachment 897314
In my setup, the bottom of the XDRs (when rotated into portrait) are actually slightly *below* the level of my mouse and other desk accessories. Instead of absurd neck-extension to look "up" at the top of the display, I have approximately equal "up" and "down" neck-movements.
As for the OP: yep! autorotation is an absolute beaut. I went to a lot of trouble to set up my arms to provide finger-touch, free rotation and movement for my displays, so that I can apply any of these layouts almost instantly:
FWIW, if any of you are trying to do this *without* a $6,000 monitor … I use this $1.99, excellent, single-purpose utility for my non-Apple displays:
RotateIt, by
Borys Pierov.