If you’re employing a porter (aka scuba sherpa) while cave diving in Mexico, they will rig your SM tanks and put regs on unless you tell them otherwise. At least the porter we used in August (full cave) tried to. I did my own.
I was being half-sarcastic. However, unless I was part of an organized dive-team, I'd have a problem with anyone touching my equipment.
However, like you say, communication can often be part of that. Some dive-charters may try to be helpful, or improve safety by trying to ensure diver equipment is setup correctly, air is turned on, etc. I've also heard numerous stories of dive-charters "helpfully" turning off one's air, likely intending to turn it on.
Most side mount divers have a hard enough time getting their OWN straps and snaps in the right place; I can’t imagine a DM at a dive op getting it right.
At some point it is no longer appropriate for someone to set up your gear (Ive never let anyone set up my gear) any sidemount diving seems to be beyond that point.
ETA: you should carry your own gear too…geez
I do take some issue with the stereotype in the first sentence. Most of us have been that slow-to-don-equipment SM diver at one point. However, most SM instructors I've seen emphasize practicing and improving your donning-speed.
I'd agree that messing with someone's SM gear (or worse, rebreather) seems several times worse.
Whether you carry gear - if you pay someone, why not let them carry your gear? I've always moved (home-moving) myself, and moved more times than I've ever wanted to. However I don't criticize people paying for movers.