TL;DR - there's no reason this type of a setup complicates anything in a situation where it doesn't need to be fully applied as long as the band has their set-up/tear-down nailed down. if the band is running IEM, they're bringing 90% of that digital mixing stuff with them anyways if they wanna have quick setups and not really piss off a sound guy by having him patch all his monitor sends over to their transmitters, and if its a place with a good PA/engineer, its easy enough to have him do his job as normal and just setup your monitoring stuff. I call BS here. "Sounding good" as in having all the instruments audible and EQ'd to the room in a live context has next to nothing to do with arrangment unless you have three bass players all playing third harmonies in the bottom end or something. You can have a terrible arrangement and still have good live sound. That doesn't mean it will sound good, but it won't be because the mix is bad. And that's exactly what putting the FOH mix in your own hands is doing if you ARE running really dense mixes. Several places we've played we have a knowledgeable engineer, and it was easier to just hand him our iPad and let him balance everything since we've already done the work of EQ'ing in and around tracks/instruments.