I sometimes go with a small-to-semi-noticeable rage boost for CGs Gohan, so I can bypass, kinda, the implications there for it being above 2x.
I always found the SSJ2 being 2x in the Boo saga as plenty, but some ppl brought up recently the argument of the Boo pod quickly filling the other half after Goku's injury by Majin Vegeta... Gohan filled half with his full SSJ2 power and Goku is considerably stronger than that Gohan.
Gohan SSJ2 : 10
Goku SSJ2 : 15
Power needed to revive Boo : 20
-- after Gohan : 9
-- after Gohan vs Dabura : 11
-- after Goku : 20
Goku (after the fight) : 6
So with those gaps and a 2x mulitplier damaged Goku would be lower than his own SSJ power. Idk, it's possible, and you can stretch the gap between Goku and Gohan more to keep "damaged SSJ2 Goku > SSJ Goku", but I just wanted to bring that up.