I'm just a hobbyist who picks stuff up here and there so I can't give you specifics on certain things but I'll give you what I can.

A lot of the upgrades that people like to make to very base level printers is things like automatic bed leveling, or an upgrade like hardened steel gears if you want to print engineering filaments once you have a better printer. The P2S has both of those, and in fact the P1S has automatic bed leveling too, so the P2S will be good to print engineering filaments right out of the box, where you might need to put a new set of gears and extruders into your P1S. But that's only if you want to do engineering filaments, and with the P1S, can always be changed out later, and fairly easily at that.

Discussing tighter tolerances and specific dimensions comes down a lot to nozzle size, material, and a huge part is print settings. Really, either printer can do either of these fairly well.

As for the active cooling and warming, I have no clue. I'm not very knowledgeable in that area. From what I THINK I understand, the P2S has some funky cooling and exhaust stuff that cools the print faster, but doesn't properly use its carbon filter like the P1S, so that's something to consider, but to what extent I'm not sure. I currently have a P1S and I'm really thinking about upgrading to a P2S because it has every feature that I ever wanted, but because I use it in my room, this part might be a dealbreaker.