The only thing I could think of is a three sided slot that would hold the deck above the frame.
The opening in the slots would face out.
So two narrow slots and one longer.
Perhaps two D linch pins could be placed in a manner so as to not ever touch the raft.
The just right pin would take some hunting.
I wouldn't trust webbing, no matter what you paid for the cam, to not slip/stetch just a little and create a toe grabber spot.
Sliding the board in and out with just two pins would be easy enough.
Other hassles would still be there.