We drive up from Austin to see my in-laws in Dallas about once a month, sometimes more around holidays. They've got a NEMA 14-30 dryer outlet in the garage and were genuinely happy to let us use it, no fuss there. The problem is my brother-in-law tried something similar last summer with his 45-pound wall-mounted charger sitting on a little shelf, plugged into a similar outlet at a different relative's place, and the cord tension over a few uses actually cracked the outlet's faceplate and loosened the receptacle in the box.
Kids are in the back seat for the whole 3.5 hour drive so by the time we get there everyone just wants to go inside, not deal with a charging setup that needs babying. I want something that's genuinely gentle on outlets that aren't mine, since we'll be doing this for years as long as they're in Dallas. What's actually held up for people using other people's electrical for a guest charging setup?