Temp Problems - Thoughts on what I did?

[Malum Argenteum]

Malum, if you don't have an air gap on the heat tape on a tub, where are you putting the thermostat? Doesn't the thermostat iteself create or require an air gap? I am going to try messing with the heat tape this weekend though to see if I can get it tighter. Do you guys think it would be bad if I put tape on all 4 sides of the heat tape?

When possible (I have ~30 channels of heat, so there's a little variance per situation, and some of my 'old work' probes are not as well installed), I put the probe in a groove cut into the shelf under the heat tape. I aim to have the heat tape in physical contact with the probe at all times (since if it isn't, the heat tape will run flat out, and the thermostat will alarm), and try to align the probe so that it touches two heat element strips (since apparently there's some expected variance between heat element strips). I usually put tape on all four edges.