The three-match simulation can be found here!
The three-match simulation with skyfalls is here!
The two-match simulation without skyfalls can be found here!
Notes:
By applying first-step analysis, I believe the average total number of combos for the 2 by 2 case is 523/525, which is approximately 0.9968951. I may have done something wrong though, although this result seems to be consistent with simulation.