Honestly, I've essentially given up on the cooled seats.
The 4th gen HSM uses a two wire system for the fans, and adjusts voltage for speed, i.e. 8v for low, 12v for high.
The 5th gen cooling fan motors use a three wire system, constant 12vdc, ground, and a PWM speed control.
So, I can either swap in 4th gen seat cooling motors (good luck finding those at reasonable prices), find a universal fan motor that bolts up (unlikely); or find an alternate control system for the 5th gen cooling fan motors (something like a universal PWM controller, but I tried one and wasn't smart enough to figure it out).
Supposedly, somehow in the TCM-2800 (I'm running Russel's 8HP70 swap kit in my '12 Ram, and ditched the 545RFE), I can also program PWM outputs. But again, I'm not really saavy enough to figure it out - there isn't a lot of info out there on it; and I'm not motivated enough to figure it out on my own vs. other projects.
It would be nice to have, but in Ohio, it's not a super important option.