Mesa 5i25 & 7i76 to GE Af-300 VFD?

You can read encoder pins directly (you dont need to figure out the GPIO pins)
they will look like this:

hm2_5i25.0.encoder.00.input-a
hm2_5i25.0.encoder.00.input-b
hm2_5i25.0.encoder.00.input-index