So, right now I have Tali in a ten gallon long. It fits her right now, but I know I'll need to upgrade before too long. I planned on putting her in a tub for her upgrade rather then a 20L for a few reasons- one, I've had a heck of a time with the humidity and keeping it constant, and I've heard tubs can help with that and it's easier to keep the humidity, two it'd be easier for ME. I keep my snake in my room, and I could fit a 30-40L somewhere with rearranging, it'd be easier to fit a plastic tub in there, and I could potentially fit another tub if I felt comfortable with another snake- definitely can't fit another tank.
I went to a pretty well known and reputable shop near my area and was talking about a issue I'd been having and their advice (I have a lamp to supplement heat because my room gets cold and will get colder, but sometimes it gets way to hot, so I don't know if I need a dimmer, timer, or just rig something so it's not directly on the lid).

Guy at the store had two points. One, I shouldn't be misting or worrying about humidity (which I was like '...what?' about. I mentioned the risk of RI's and he was like 'we never mist and its never happened to us, so don't worry about it. uh. ok then') and two, tubs are only used in a breeder set up so I should just leave my ball in a tank, keep the heating, and not stress about the humidity. So, I was wondering, what do you all think for tubs for pets? She's not really a display animal, so I don't care much about her being able to be seen ALL the time.

He asked me where I heard that about humidity, and I was like 'google, and every caresheet or bit of information I've read, and every hobbyist I've talked too' and he just rolled his eyes. Like, I'm a little boggled. Maybe the humidity is up high enough they've never had an issue in store?