I'm interested in this topic, too, though my symptoms are slightly different than Ron's. I've done very little to deal with my problems other than to put a strap clamp around one part of the filler hose (between the inlet and the wall and the metal pipe connection to the the tank) to keep if from creating a kink and a resulting flat point in that hose. All the clamp does is force it to stay round.
Mine fills very slowly, kicking off even the very slow RV pumps at Flying Js multiple times. I have to manually hold and very lightly squeeze the satellite pumps (my filler is only on the passenger side) when I use the truck lanes. On the slower RV lane pumps, I can generally set the automatic feed after I've put in 20-30 on a 1/2 empty tank but usually not before then. Even the slowest speed on the satellite pumps kicks the automatic setting off in less than a second.
I've considered completely disassembling the filler plumbing, looking for an obstruction. I've always assumed that the problem was caused by poor engineering on the vent and that there was little that I could easily do about that.
2000 Georgie Boy Landau 36' DP
2005 Saturn Vue toad