Just as a little update, I have decided on the CHE route, and purchased a 100W CHE and some clamp lamps. I'm considering purchasing another tub of the same size as my enclosure to test things on, and so I can safely cut out a hole in the lid without leaving room for escape artists while the modified lid fumigates. Probably the most practical thing to do, y'know?

I might post some pics of progress if anyone's interested, but honestly I might not even remember by the time I get to it lmao.