well done
you have followed the basic engineering principle
K.I.S.S.

I tried a very similar approach. Though I used some rubber with turned up edges I got from Clark rubber, even had a quick release where the strap attached to the leg rope plug. It went well for two surfs and then I went for a floater, crashed, my feet and legs went under and through the strap and my board was now tight against the back of my thighs. I was now face down in the water getting pumped and couldn't get to the quick release. After the wave passed I managed to get my legs out. I then went to the beach took the strap off and never used it again. Be careful, by the look of that you could get stuck in the same position.

Be careful it looks dangerous, knee twisting or getting caught by the strap.
Either straps on or clear deck (Both have a place)
There are straps designed for a race board. Very light weight and flexible (expect not so strong) but when not in use they flatten onto the deck and can be walked on, just a knack to then getting your feet in. Still trying to track the supplier.

Yep I can see a few potential disasters happening with your setup why not just a single front footstrap as in the vid posted by griffin kites in the best light wind kite topic,you can get a stick on strap pad setup if your board dosent have inserts,gonna give the single strap a go myself,could work well.