Congrats, Fod and buddy!!!
That also was my first impression with jumping in Map 2. You are simply not prepared for the rear wheel to stop while you are up in the air. It is much easier to start in Map 3. But if the jump is long enough, then Map 3 will pull your front end down as well, eventually. So, you have to keep the throttle partially open while up in the air. Once you learn that and it becomes automatic, jumping in any map, including Map 2, will not be a problem. I now actually prefer the engine braking in Map 2 and may want even a bit more of it. It helps with stabilizing the bike when entering turns.
Yes, I had the same observations about the stock rebound settings as well. Riding a demo bike I had both rear clickers -- compression and rebound -- fully in.
I haven't taken my own MXR to a track yet (it is raining here for the next 2 days
, but I already put 7 miles on it in my backyard
!). I will know more after I take mine to a proper MX track.