This reminds me of the issue with trying to get a 5.7 car PCM to run the SRV module. The 5.7 PCM has a setting that can be flipped in HPTuners (at least I understand it does), but nothing happens. This has to be related to the OS and that the logic is missing in the 5.7 PCM, so even writing a "full" 6.4 tune to the 5.7 PCM doesn't make it work. It just doesn't have the logic to run the SRV module in the 5.7 OS.
This is starting to make a little more sense to me know. I always wondered why they could make the SRV module work, but I assumed it was because they hadn't found the right table or something. But the idea that there is an OS with logic that uses the tables, and the OS (so far?) can't be overwritten, makes a ton more sense.