When I deadlift, I'm using left hand over, right hand under. Are there any differences if I switch the hands? Are there any benefits to switching or cons to not switching?
Ideally, on all of your lighter sets, you'd be using a double-overhand grip (both palms facing you) to actually work your grip as well as the rest of the posterior chain. If you keep your mixed grip work to just the heaviest sets, it doesn't matter as much if you switch them. Yes, the muscles of the forearm and shoulder end up getting loaded differently, so if you deadlift heavy, often, you might develop imbalances. But if you're a competitive power-lifter, that's probably an ok trade-off, and if you're not, you probably aren't deadlifting so heavy or so often that you need to worry anyways.
FWIW, I used to switch up my mixed grip pretty regularly, but over the past few years, have settled on having my right hand switched on the heaviest sets, and haven't had any issues at all. Yet.