Here this will make you laugh: I love GJ guitar full stop, but love playing my archtops just as much, more sometimes, and I am crazy about flat wound strings. I like the feel on my fingers and I like the tone.
My GJ guitar has all the volume you could ever want, and top end galore. But - even though it has the Favio size body, I would love to get more bottom end on it.
So - could you even try to use flatwounds on a GJ guitar? I would imagine the tension would hoark the neck, and I am sure as hell not going to try it on mine - but has anyone else ever thought of this?
There it is your laugh of the day, enjoy!