Hot take: I laughed at the $22 tinfoil hat trick for my offset, then it held 225 for 11 hours straight
My neighbor in Tulsa kept swearing a foil-wrapped water pan turns a cheap offset into a set-and-forget pit, and I told him that was nonsense until I burned through 40 pounds of charcoal in one cook. Now I want to know who else runs a baffle or tuning plate setup, because I think I just got lucky once and need to hear it from folks who've done it 20 times.
Watched a buddy in Tulsa do the exact same thing with his cheap offset, and he swore by that foil water pan trick too. He ran it for a whole summer of briskets and butts, and every time he'd pull the pan out it looked like a crumpled mess, but the temps stayed steady as a rock. Thing is, he finally admitted the foil wasn't really the magic, it was the water pan blocking direct heat plus keeping the pit sealed up tight. He tested it once without the foil and just the bare pan, and the results were close enough that he quit bothering with the wrap. So your 11 hours might not be pure luck, but it also might not be the tinfoil doing the heavy lifting. I'd say run it again three or four more times the same way and see if it holds before you trust it.