I completely understand RG,
Drummers aren't the brightest crayons in the box, and it's even worse when they can't keep a steady meter. Dynamics is a concept that escapes about 99% of the so-called Percussion Engineers out there.
Very much like the average guitar player who gets terrified at the word "Programmable" because he believes that and the word "Amplifier" should never be used in the same sentence.
I've had to compete for airspace with drummers like that in the past more often than I'd like to admit, but at least the ADA rigs make that easy. My levels are usually at a point where if I turn up my volume on the guitar, a couple of my open strings will begin to feedback. Usually they are the A,D and G strings. It doesn't have to be frightfully loud on my end to do that either, but when that happens, I usually have to tell the drummer to tighten his snare bands.
The EQ settings can help this happen at lower volumes though, but you need a Spectrum Anaylizer to see where all your feedback shelves are. Sound men usually have these things at larger venues to see where their frequencies are clipping. so they can trim those EQ bands down.
I like multi-frequency feedback myself because that allows me to bend a feedback note into another feedback note or chord. An example of what I'm talking about would be on one occasion, I was pinching a D note at the 12th fret, which began to feed back very nicely, then I bent that up to an E note while it was still feeding back, which struck a harmonic frequency with the open E strings, and they began to vibrate and feedback also. At this point I slid down to an open E Maj 4th (Sus), which just began to feedback across all six strings. There were harmonic shifts and pitch changes in the feedback through all of this but it was very musical, and people later asked me what kind of effect was I using to get those crazy sounds. That was too funny.
Harley