A couple of thoughts ...

Some ball pythons are just great shedders ... they will get it all off in a tight little "wad" no matter what the humidity in the cage or even the conditions. Others, are just always bad shedders ... even with perfect environments and humidity, their sheds are always flakey and stuck ... I have a few hypos that can be especially bad at times ... I have a personal theory that some ball pythons have "thinner" sheds than others (from birth, many of my hypos seem to have had thinner sheds in general) and that thinner shedders are usually poorer shedders than thicker shedders.

As far as thermometers go ... I have several hundred cages in my shop and not one of them has a thermometer in it all of the time. On a regular basis, I place thermometers into random cages for 24 - 48 hours and record the high/low temps to make sure everything is working like it should, but for the most part I rely on my thermostats to do their job.

Not sure if this helps, but I felt like posting it anyway.

-adam