So I finally got my proofing fridge up and working, and bulk fermented (75% WW, about 85% hydration) a 1000g batch at 65F / 18C. I usually BF at 73F / 22.7C. It went too far, almost to 2x volume rise; I try to aim for 1.5x-17x. But when I gently dumped it out to bench rest, it came out of my cambro 6-qt cylinder completely clean. This has never happened before and it really blew my mind, especially since it was over-proofed. Shaping was much easier than I expected, as well. Although the oven spring was weaker, as I anticipated.
I have never read anything about how a lower temp BF would change the stickiness of the dough. Looking forward to experimenting more.
Actually, I have seen accounts of people kitchens being at 65f, but that's just inhumanly cold. Also inhumanely cold.
If you know how to use it - it's fine. Enjoy!