You are not saying whether this is the 17 foot or the 18.5 foot version. The longer boat is also a bit deeper, which would cover larger foot sizes and more gear.

Sheer, or gunwale height is really not the problem because, as you noted, the deck height is variable. You can give yourself as much foot room as you want. Besides, the deck itself is soft fabric, not solid wood, so really big feet will just poke it a bit, it will stretch in that direction, and go back to normal when the paddler exits.

If larger sized people are asking to borrow your boat, tell them to talk to us. We'll tell them how to build their own boats which will fit them better.

PGJ