I asked them about P+ And they said they’re looking into it but they said they were more hopeful on SR / LR with 980 motors. I think they’re actually working on it tbh. The 980 motor opened a huge door for them to tune.
AFAIK they haven't offered for sale any proprietary "tuning" at all.
The 2 products they sell are basically copying Teslas acceleration boost for stage 1, and copying the stock P code for stage 2 (hence why they have the same HW limitations as Teslas offerings)
Regarding the RWD cars, AFAIK the rear motor doesn't have a ton left in it above what it already outputs on the RWD vehicle.
If it did it seems Tesla would already have offered a paid AB option for it.
I also vaguely recall some EU disclosure docs back when everything got a 980 showing the LR RWD and P both had the same max rear output- with the LR AWD being lower despite being physically identical- and the front output on the LR AWD and P being different against despite being physically identical-- it's probably linked somewhere in the 97,000 page debate on the 980 stuff