Update on this challenge:
I purchased this OBD splitter (Amazon:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1)
Make sure JB4 is connected first and on extension #1.
Everything works well! Both JB4 Mobile and TrackAddict apps are working well, and you can switch JB4 maps and then record sessions using TrackAddict!
Only caveat is that once you set the map you want, avoid switching back and forth between apps as that will kill your session in TrackAddict.
Cheers!
gec
PS - JB4 map 3 and 5 (with the right mixture of E85) are making the xDrive M3 an absolute beast, which is amazing to say about a car that is already a freaking monster. Map 5 results with much more boost, and maybe slightly less smooth comparing to map 3. Both maps are pure joy! Just match the right map to your circumstances and driving style.