90 degree rotations are by far the most common for 3D models.
If another rotation is needed for some reason it’s unlikely some preset will work, and just typing in a number is probably the best option.
As a tip for all (copied from the mentioned gitlab-issue): Maybe the use of the scroll-wheel and Shift+scroll-wheel can help someone:
rotation:
scroll-wheel alone: ±90°
Shift+scroll-wheel: ±1°
linear movement/offset:
scroll-wheel alone: ± 0.5mm
Shift+scroll-wheel: ± 0.1mm
(admittedly, I for myself have never used the scroll-wheel at these number-entry-fields in real use. It’s to seldom that I have to adjust these settings and so I only use the obvious possibilities - direct number-entry + arrow-icons without any modifier-keys)