Good question, I don't have an answer for that it is personal choice. I just wanted to give the op the the advice that was given to me. It made a difference in my set up I stopped seeing the swings I was with the probed heat source set ups I have (I have some that are and some that are not) Logically if the T-stat is set over the temp desired and heat conductive tape is on the probe and the room gets warmer the enclosure will get disproportionally warmer as well. It makes sense to me but every set up is not the same you may have a stable room temp so the tape is always the same temp than everything would be stable.
Stability, how ever it is maintained is the key, it lets us know that WE have control over that carefully balanced little chunk of Africa in our homes.