Update:
Camper tape absolutely works for all night pumping. If you grease up thoroughly and start with medium pressure for just a few minutes, you can pull enough breast tissue into the cups to hold a seal, then release the pressure and switch to the low pressure “smartbox” all night. With two layers of Frost King camper tape, it was surprisingly comfortable when I sleep pumped for 11 hours last night. It’s probably important to mention that I used contoured cups and positioned the most concave part of the rim to line up with my armpit. I think that helped a lot. It was still nowhere near as comfortable as the Brava domes which are absolutely painless (aside from the skin irritation most people eventually get from wearing adhesive silicone for so many hours per day).