We have belonged to clubs that do not have beaches, and in those cases both monohulls and multihulls usually launched either off their trailer using a concrete ramp or off the wall using electric hoists. One place where we had to launch the cats over a concrete wall, we carpeted the heck out of the wall and just pushed our boats over. Getting them back out took considerably more manpower, though.

It sounds like what you already have is the best possible way to deal with it. If the only problem is screws popping up, wouldn't the best solution be to just replace all the screws with nuts and bolts (nuts on the under side) and countersink the bolts on the top side?