I was only referring to a probe being used inside the enclosure, and not with a UTH. I agree with you that there can be some unwanted factors like the snake laying on the probe, or liquid contacting the probe that will change what the thermostat is reading; and you're right, the probe is better placed off the ground to eliminate those problems.
Yep. The probe can certainly be off the ground just as long as the heat isn't coming from the ground.