I was a little surprised to see that this is the way it appears to be done. I guess you just put the probe on any one of the pieces of heat tape/flexwatt? And it just provides uniform temps because all the shelves are the same?
Do the higher end thermostats give any special features that help better manage so many tubs at once? I assume not, since it only has one probe, so it's really not able to know about all the tubs.