There are two different length retainer screws. Mine on the Tabou, were working loose as well

I dont like the Tabou foot straps, as the inside edge as it meets the board is rather hard. Anyway I digress. I purchased some slightly short retainers from Sail n Surf over here, then went and purchased a Philips head with hardened tip. Fitted and all tight and good.

My original when I measured came close to, or did bottomed out as well
Fitted the 115 with JP straps, but believe there are other options as well.

So shorter retainers (screws) and hardened tip Philips head so it doesn't wear quickly and not allow good torque on the screw head mating star point