With rims of this standard width, the tire's bead becomes the issue, IMO. Small or large diameter, if the bead is too thick, like, say on a Schwable Super Ultra Marathon Anti-Flat 8000 Touring RhinoForceLiner XX-Tra Tuff5X, then the tube's valve stem can't be wedged in between. Folding bead tires tend to be a lot better about this, regardless of tire diameter/size. I run 700C Mavic MA2 rims (same profile as MA40s) with "33mm" Soma Supple Vitesse EX tires with zero issue. The 33s measure closer to 30mm in width. I've also mounted those same Somas in 38mm size (36.x actual width) on those same MA2s and they were totally fine.

The whole "2x the inner rim width = max allowable tire width" is a nice starting point, but there are other variables in play, and as other tire threads have seen, old MTB tires were mounted on narrow rims like these, and it wasn't the end of the world. As long as your bike has the brake bridge, fork crown, and chain stay clearance, 32s won't be a problem. And if the bike came with 27" wheels originally, it should clear even easier.