Mark

good luck with the throat opening procedure. You are already lucky to have a 20FR as I started off with a 12 FR which leaked and they would only bump me to a 14FR which cannot take anything thicker than Jevity.
Have you considered VitalStim? NIH is doing a clinical study on E-stim for swallowing. Here is the link with general overview of NMES therapy plus where they are accepting patients. NIH Estim for Swallowing
I am on my second round of another 12 treatments and while I can do 400 "forceful swallows" of "thickend" nectar, still can't pass the dang Modified Barium Swallow test and aspire both thin and "honey" solutions. Like yourself, I tolerate the PEG while focusing on learning to swallow again.
What is your treatment regime?