Modular Boulder Training Board

All boulder halls are closed and I thought now that everything is on Corona-Lockdown this migth be the perfect oportunity to design my personal training board.
I had a some spare wood and M5 drive-in nuts laying around, which I used as a base. I wanted to have a modular system, as I was not sure what the correct gripsizes should be, but sofar my first try works out quite nicely.
I cannot say much about the stability so far, I weich 74 kg and the grips seem to be solid enough, but I don't know how the ling term sability will be. I printed the parts with 1.2 mm thick walls and 40% infill, which for the moment seems enough form me.

The hexagons have a width (flat-flat) of 76 mm, and the holes for M5 soclet head cap screws.