When I was mounting the foot braces I worried about that beause of the way the thin Luan plywood dented in when tightening the nuts. Washers, I think, would pose another problem - sealing the hull breach - by adding another layer to seal. So I am shopping for bolts with larger heads, something like fender bolts on the smaller scale and in stainless. I am also wondering if I should use Gorilla glue or resin to seal the breach instead of the marine Goop I am currently using.
BTW this boat is still amazing me with speed and versatility. I actually sat side saddle in it for a while to cool my tootsies in the water. Managed to get onto some stumps but the graphite hull worked great in just paddling off the stump. The trolley and stake out pole combo worked great in a moderate wind. I have install the larger seat mount base at the bottom of the pedestal and that removed the bottom flex I was experiencing with the narrower bottom. I am still using industrial velcro to secure the seat unit to the boat.
One other thing, I haven't noticed any hull slap in this boat. The Big Game plastic boat always had a fair amount of hull slap even in mild wind.