Misfire only when hot?

I'd say you could try to run some fuel injector cleaner through the injectors that could clean out any extra carbon build-up because if the fueling system is giving it that extra bit of pressure it could just push through the build-up but at higher RPMs, if's having trouble getting through the injector in the lower range then that would make sense. If you think it's the PCM you could get something to read what the PCM is seeing and how much it's demanding out of the injectors. I'd check battery voltage if the PCM is getting a few millivolts under what it should run the PCM could be in that sweet spot that it'll run the car and be on but at the same time be putting out a dirty signal then when you rev up the engine the alternator charges the battery and gives the PCM proper voltage. I would start with the fuel injector cleaner and check the battery voltage.