I have a PSC 31 but no A/C but always some opinions...
I didn't like the idea of Tee-ing off engine thru hull so I added a new one under the sink. My aft berth is essentially a garage and that's where I'd put it if I could - perhaps in that stern locker on port side if I needed the berth.
There's too much weight already on the starboard side.
PSC 31 #84