"2 is good" as a baseline but I definitely think that having it scale with character level may be a good idea too. In tabletop D&D there are four tiers of play, 1-4, 5-10, 10-16, 16+. Larian hasn't settled on BG3's max level but it's probably going to be somewhere in that third tier. I can imagine basically getting an extra short rest as you go up in tiers, having a max of 3 or 4 at high levels when you have more HP, hit die and short rest resources that you'd need to recover.
Alternatively, peg short rests per level to single-class proficiency bonus?
