The local VIOC place has a huge sign "hiring friendly people" they don't care if you know about cars. Then again really, it's not that hard. They straight up decline doing an oil change on any iffy vehicle. Leaking, drain plug look bad, etc? "Sorry, we aren't allowed to work on your car, you'll have to take it to a mechanic". So that pretty much solves the problem because it's hard to mess up an oil change unless something is broken already. At least around here most cars that go through there are newer/Euro cars. And I don't hear about tons of issues, mostly positive reviews. Personally I've gone there once or twice, when I've been too busy. And I know some of the people working there. I would have no hesitation sending people there... VIOC has their stuff together and if something happens, they will probably take care of it.
Although they do often try to upsell $50+ for an air filter or cabin air filter for old/basic cars. I'm not talking about cars with $40 retail price air filters, then I'd get it). Many people come in to my store which is like two blocks away and ask for air and cabin filters because "Valvoline down the street wanted over $100 to change both" and I sell them $30 worth of filters and they're happy.