Absolutely! It's part of being professional at all levels. Now, having said that, I'm in a bit of an unusual situation with a 12 piece band that includes 5 horns and 3 lead vocals. With that many people, it's important to have a plot. Anyone who hires us knows we're a big band. Early on in the negotiations, the discussion of stage plot and sound requirements are talked about. Included with the stage plot is a line send/return schedule that is pretty close to 30 channels.
We're currently building a new monitor rack for our IEMs and everything needed on stage. We'll have a 96 pin labeled connector and "short" snake to hand the FOH tech. Idea is that wherever we play, our stage sound is a quick, repeatable setup and it makes the FOH tech very happy too.
I realize not many bands have this kind of setup, but even so, this should be a part of any pro band's negotiation and contract...did I mention contract? If you're playing somewhere other than your local venue where you have a successful history and other bands have worked without issues, you might get away with it...but if you're playing a bigger venue/stage/show, do yourselves a favor and get a signed contract with a deposit.
Beyond that, if you can get contact info from the producer for the sound company, it's a good idea (and courtesy) to touch base with them to see if they have questions and/or need anything additional from you.