While looking for pvc enclosures, I came across Apex Reptiles. I really like the modularity of their enclosures, and given the 6-8 week lead times I intend to order soon. I'm tempted to get a 3x2x2 (instead of straight for 4x2x2) since I could expand it later if necessary, but I think sticking to 2 foot increments will give me better stacking compatibility with other enclosures.

The Apex Reptiles website swears pvc insulates too well for UTH to be safe. From what I've gathered here UTH is necessary, and heat tape is typically used with pvc. Am I correct that the UTH is necessary, and that I should ignore the website's warnings?

I plan to maintain ambient heat with an 80W vivarium electronics radiant heat panel and a pulse-proportional thermostat. Should I put the heat tape on a pulse-proportional thermostat as well, or will the on/off thermostats I'm using in my current setup (for CHE and heat pad) suffice?