I thought it was that the VSS code would get set with a higher stall?

You should be able to enter low mph upshift settings into the kickdown tables and then use the rpm table to select the shift point. I've never read anything that says you can't tune for the converter, just that the car won't shift with a bigger stall when it's a stock tune.

I had to fix my PCM in the fall. I tried to change a table in Tunercat while flashing - don't do this....