I won't take the discussion in this thread any deeper, as I don't want to derail the OP's original question. I'll just say that there are multiple reasons that have caused me to conclude that providing the option of UVB to all of my snakes is something I'll continue to do. It's not a question of whether my snakes must have UVB in the same sense a bearded dragon requires it. It's that I want to provide optimal husbandry, and some things that are optimal are definitely not required for survival. But adding UVB has to be done carefully and thoughtfully, and we have to always be open to new information.
I'm absolutely up for nuanced discussions. I put a big premium on courtesy and kindness, and often avoid the usual debates on husbandry found on other social media sites (and occasionally even here) because it just isn't useful when those discussions devolve into arguments or "I've been keeping snakes longer than you", etc. But if we can ever put a thread together to simply share citations and references, I'd be glad to contribute.