Do Not use tape inside the enclosure! The only possible exception might be painters/artist tape since it has almost no stickiness. Even foil tape is a no-no!
The best way to set things up is to foil tape the UTH or Flexwatt to the bottom outside of the enclosure, then tape the thermoSTAT probe directly to the UTH. To secure the thermometer probe, place it under the substrate against the enclosure floor and cover with substrate and the warm side hide. The hide will hold the cord down and make it harder for the snake to move it.
IMHO, having to reposition a probe is a lot less trouble than having to take a snake to the vet after it got caught up in tape.
And just because they've never encountered the tape before does not mean they won't later.