I've owned my '16 GTI since 2016, and for the majority of that time i've been on a JB4. I've got a couple bolt-ons, and I've messed around with the settings here and there on the jb4, as well as recorded loads of data logs. But my gti is my DD, so i don't really spend a bunch of time messing around with the (limited) settings on the JB4, and i've left it on map 1 for a long time now.
I do have some experience with the mpvi2. I got one to use for ls swaps, and project vehicles. I hooked up the mpvi2 to my GTI recently and downloaded the factory tune file, just for shits and gigs. I'd be happy to help in anyway that i can, collecting data logs, logging different parameters ect. ect. I'm not volunteering to be a guinea pig, but as a fellow enthusiast, if there's anything i could do to help further the research of this new platform I'd love to help!