Yes, I have the adventure controller. It works with DMD2 and Guru Maps Pro.
Garmin exists primarily for aircraft. That is their main business. Everything else is just there.
I figure to eliminate the DMD2 because the old 990R is not compliant with the engine metrics part of the tool and I'm unlikely to bother with roadbooks much in the future. The Tab A7-Lite is very limited as far as storage. DMD2 doesn't use the memory card for maps or routes or roadbooks so becomes a memory hog.
Guru Maps Pro store maps on the card just fine.
Playing with roadbooks led me to DMD2 initially because I was looking for a bar controller then playing with the Beta app I liked how they handled roadbooks, which is specifically why DMD2 was created, not as a map-based navigation tool.
The controller is the three red lights and toggle stick next to the left mirror on the bar.