I’ve gone by the size guide Prendas gave me when I bought my first pair of bib shorts
It goes along the lines of:
“The waist size is pointless, that bit can stretch as much as you need it to. The size you need is in the height and leg length.”
Followed that with the 2 bib shorts and 2 bib tights I have, and right enough they’ve coped with me dropping from 95 kilo down to 68 and back up to 75 as well as daytime bloating fine.
So, if the shoulder straps are digging in then you’re probably a size too small.
IF they are feeling a bit tight on calves and thighs double check whether they are meant to be compression tights, and then don’t worry about it, again that’s a stretchy bit designed to be worn for leg sizes between Rasmussen and Hoy.