Good tips Duck! They really should be called thinessers since that's what they do.
I almost exclusively used sleds for all my thining needs. Bonus is that any compression of the conveyor belt with narrow stock is eliminated with the large sled surface area. Also the sled area gets a good grip to the conveyor so no annoying slipping.
Helps reduce the snipe when the drum makes first contact and allows for shorter stock to pass through.
The fence only needs to be high enough to catch the stocks edge. My fence is at about 1/4" (could be lower) so when I'm sanding something thinner than 1/4", I will place a square of 3/16" masonite hardboard underneath to raise the stock up.
Keeping an air hose handy is good to blow off the sled after each pass. This clears the sawdust (sandust?) away so the stock sits flush for the next pass.