I thought it would be the manual method.
Guru, the reason is, in my case anyway, I don't want to switch to a patch and WHAM you're bending the vu needles :) I like them all reasonable.
What I normally do is have the cleanest least compressed patch, create one of you don't have one, strum it really hard and adjust the patch output level with my interface input knobs central and the master output volume central. Then I save the patch and use that as a reference. When I create a new patch I put the knobs back central, play the reference patch, note the db, pay the new patch and match the output.
I know all that about perceived volume but this is just to stop you jumping out of your skin ;)