I think you would really benefit from a Rtech map, huge midrange increases can be had, and once mapped it won't need touching.
I've had a revo map but it was at second choice to R-tech!
But ultimately if you are happy with how the car drives on Stg2 then that's fine but that's quite a chunk of midrange you are losing out on by stepping back.
The issue is a mapping issue, sure you can fix it by physical changes to turbo, clipped blades etc, you can map around it and unfortunately Revo does not offer the adjustment to circumnavigate the problem.