Thanks for your ideas. My main goal is not really mass gain, but strength gain (with the necessary mass). I am somewhat deficient in the pressing movements like HSPU and press-handstand. I work on this by doing workouts like J.T. (21/15/9 HSPU, ring dip, pushup) weekly or so.
Tumbling for me is not active rest! Anything more than a slow cartwheel requires a lot of power in my opinion. I want to get proficient enough so that I can RO-BHS or RO-Btuck outside of the gym, but right now I am not to that point.