Bob, MTH went to four pickup rollers (a pair on each truck). I assume they did this because of problems like you are experiencing. I wonder if you could install the twin-roller pickups on your SW8? I believe they made the change about when 3v PS2 was released.
FWIW, my PS# SW1500s (4 pickup rollers) never hesitate no matter how slow I run them through Fastrack track switches. To be fair all but one is O72 but my one O36 track switch works flawlessly as well.