As far as the big hides go:

Id go with just the one, placed directly over the hotspot. This will trap your heat nicely, so he'll get a little extra ambient heat in the hide above what he'd get just laying on the tape.

You could also go with no hides and see if he does well. Most adults in tubs dont really need the hide, the nature of the rack helps a lot with their level of security. Thats totally up to you tho.

As far as the other stuff: you want to use your temp gun on the newspaper, not the bottom of the tub. Temp guns cant take very accurate readings on a clear surface like a tub. The difference in temp between the newspaper and bottom of the tub will be minimal, not nearly enough to be worried about.

Your temps are always going to vary a bit from tub to tub. Those snakes that have a slightly cooler tub will bask slightly more, those whos tubs run hotter will bask a bit less often. If you want to you can always experiment with moving snakes to different slots. You may fine certain snakes perfer the cooler vs warmer temps. Regardless its really not an issue.

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