904 Reverse/1st gear issues

I agree with you. I can do a pressure test while I have the pan off too! I don't want to keep dropping the pan
No you can't. I'm talking the oil-pressure test at the L/R pressure port; the oil still has to be in the pan, and the engine running at 1600rpm

You may be thinking air-test with the VB off. That would be the 3rd test.
First oil-pressure
then inspect servo adjustment and strut install
then air-test