Got to laugh at "swim out to retrieve my boat at a primitive ramp." Just hope no one was there to see ya, including snakes and gators! I have had to do that and damn, there was a group to witness it!
Hole for the riv nut .250" Hole for 8-32 tap is .1360", so the hole is not that much larger. I think between the riv-nuts and the E6000, (ladder is made from 316 SS), it will last longer than the boat!
Good suggestion for the grab handle. I have a Talon that I can lean against and use for additional support.
Thanks again and tight lines!