Helpful soundguy goes "So do you use your thumb, your fingers, a pick...?" and I goes "Yeah". He looked a little puzzled. So I helped him understand that we'll give him a good, representative soundcheck, then to relax, cuz I'll be switching dynamics, techniques, eq, instruments, and fx with each song as appropriate, but he'll get a good signal and he doesn't have to chase it. I can tell if it gets boomy, and I can tell if you can't feel it. The gp and I are both wireless, so we're able to roam during check (and the set), and we have an experienced entourage (family/friends--I'm not trying to be pretentious) that can give us additional feedback, esp after the room fills up.
I do expect the sound team to limit extremes, prevent feedback, and otherwise present the cleanest, more representative sound experience--and to work with me on achieving it. And the gp and I have worked on keeping off each other's toes sonically, so those boundaries need to be maintained. I never expect perfection, and I expect it to not be a disaster. It also helps that our regular sound guy represents when we're in a venue with their own system, and watches them like a hawk. We're pretty easy to get along with--life's too short and I'm too old, etc etc--but even then once in a while you're in a place with some guy and he's just not not gonna show off those new subs, or doesn't understand phase issues or...