The cherry is pretty stout stuff, and I haven't had any problems with it. The cohesive strength of the wood is pretty high, and it is glued in all around the circumference with epoxy. I suspect that a tug strong enough to pull out the rod would break the small bungee first. As a test, I have picked up the 38 lb. boat by the bungees only, and nothing failed.

Water in the rings doesn't cause trouble either, because my roof rack carries the boat edgewise, and the water gets dumped at least once per day. On a long camping trip, just flip the boat before you turn in. There is enough epoxy in and around the assembly that it would take months worth of immersion to cause real problems.