I agree it is a simple matter of testing the gain and making a few minor potentiometer adjustments. When working with circuits in tandem I think a good saying is “just because it goes to 10 doesn’t mean it should”, especially for any guitarists that would not concern themselves with such things.
What a fantastic build. Well executed on the inside & out and should make a great combo for any rig. That is the kind of combo I would take to a local Jam Night and let all the players have a go at it. I would call that the “puppy dog sell” and then take orders to fund your hobby. I have certainly done it.
I would add that Billy’s link is a great source of info that is so often overlooked.