It has been 1.5 years since I bought my 550SE and having moved country I haven't flown for about the same length of time; I'm only just getting round to finishing the build.
I think I have everything set up correctly, my only problem is that when I alter the gain on the 8FG it doesn't alter on the VStabi setup page. I never quite got used to the logic on the 8FG, can anyone tell me what I should see on the gyro screen?

Proficient at turning cash and credit into smoke and noise!

You have 2 "gains', one in the Vstabi and one on the radio.
I don't remember how to disable the one on the Vstabi so you would be able to do it on your radio.

on the right in the vstabi screen
under the setup button you see active bank selection

change bank 0 to aux gyro gain

Insha Allah made in america

Exactly as the wicked clown says , you need to assign the gyro gain to be controlled by the tx