If it only it were that simple. I was reminded recently that part of the challenge of dealing with electric guitar players is that, for many of them, "their tone" is what's coming out of the amp ~45° off-axis and at least 1m away, and what's being perceived by a typically-on-axis microphone (or the poor sods on house left, for that matter) "doesn't sound right" regardless of the fact that it's what the audience will actually be hearing. It's why many guitar players don't want their instrument in their wedge (and IEMs only make things that much worse).
I once had a loud-enough-that-the-drums-needed-reinforcement-in-a-smallish-venue guitar player explain to me that he once tried a tilt-back on his amp but it "really caused him some problems". Or there was the one who mentioned that he couldn't put the amp offstage somewhere and rely on his monitor mix instead because what comes out of the wedge "always sounds too harsh and it causes me to play timidly".
-Russ
I've had similar conversations with guitar plays about about leaning their amp back on the amps built in kick back legs so they could actually hear their amp!