I like the way you think!!!!! Punchin' mats is the BOMB!!!!
I used the 3.5" and the issue I had was with the thick vegitation here, the tail ripped right off after the second flip. Guess the "fingers" catch in the mat to much. I had same issue with 4" swim toad. Feet tear up to quick.
Shot some in hard though se we will see.
What we need is a slight modification

where the feet attach to the body and at the bend where the fingers start. If they were built up a bit, I think they would work. Either that or the feet could be made thinner and they would not catch and hold as good.
Lets go mat punchin' in this 100+ heat!!! The big girls always get deep in it this time of year!!!!!
Jim