Anyone serious into Reptiles and breeding 9 times out of 10 will NOT have the probe inside the enclosure. Why, theirs no need to have any wires in the cage with an animal that is strong enough to move it regardless what you use to hold it down with.
Why risk the potential hazard of injuring the snake if something goes wrong.
People can disagree with me all they want, I been around longer than most and ive seen it all. I go by first had experience on what works and what doesnt.
Do as you wish, but when that day comes, Ill be here saying I told you so.