Well, all I can say is that this is one of the main reasons for me to love modeling and fullrange monitoring.
Especially with a 4x12 in smaller venues, there's always gonna be issues arising. Someone will get the full blast and then that effect wears off quickly as soon as there's folks in front of the stage (as in your case - defenitely doesn't help that the stage isn't raised, either). To make matters worse, especially with a 4x12, it's quite difficult to slant it properly, so that someone receiving the full blast typically isn't you.
IMO, for a 4x12 to work well, the only decent option is to place it quite some meters behind you - or rather a little on one side, simply because our ears don't perceive sounds coming to our back too well.
All of this is no issue anymore instantly once you're using a "FRFR" wedge for your monitoring duties.
And yes, I am absolutely aware of that can of worms. Just personally, I couldn't be any happier and whenever I have the choice (which is pretty much always), I will not use a traditional guitar cab ever again in my life.