Brian, I have not had trouble with my bees overheating. If I were to lose power I would simply separate the vac section form the catch box section. I googled bees overhearing after being vacuumed after a cutout. Here is what I found. 2013 It looks like all roads lead back to here, beemaster. 
The following is just a sample of things that can go wrong. I have not experienced these negative experiences. I do not think when Robo vac is used as purposed, it does not either. I did not read the entire thread only the first two post.
Glad you have not had overheating issues and hope you never do. However it IS a possibility. Many people feel foolish when issues arise and bees get killed in a situation they could have prevented and therefore don't necessarily make it public knowledge, so I'm not surprised you didn't find more. I killed bees from overheating in my early cut-out days using the old box in a box bee vacs and people continue to kill bees via overheating on a regular basis.
There are many situations out there that this can happen and having a plan in your pocket to "shut off" or whatever when a hose clog happens doesn't necessarily prevent bee loss. It is like saying I would never drive into a ditch because when I see I'm heading for the ditch I will turn the steering wheel to avoid it. OK, seems like a reasonable idea but yet how many people drive into ditches?
You are 20ft up on a ladder neck deep in a removal and you need both hands and set the vac down and it sucks up a rag, chunk of insulation, or just sucks to the wall. Best case is you notice and now have to potentially do something with the honey laden comb that is dripping in your hands and then climb down 20ft of ladder to deal with it. Worse case is you don't notice and continue on with that sticky comb and the next, and the next and go back to use the vacuum 5, 10, .... minutes later and realize there is no suction.
Even a more probable case is you suck off a clump of festooning bees and it clogs the hose and now must climb down the ladder and deal with it, it all takes precious time. Or simply drop the hose and it sucks to the ground, once again down the ladder.
Point is most bee vac will work under ideal situations, but unfortunately doing removals is rarely in ideal situations. Some bee vacs are better than others when dealing with overheating. Bucket types are the worse because they are a small volume and bees need to spread out to cool themselves when hot. For the most part it is a learned discipline on how many bees you can suck up with a bucket vac before changing cages as there is no visible way to see how full it is. I strongly discourage using bucket vacs, they kill more bees that all other bee vac designs combined.
I have multiple customers in Texas that have tried many different bee vacs and could never get past overheating until they got my vac. Now they put a dawn comb filled with water in the vac before starting and have overcome their issues.
There is no one perfect bee vac and it all comes down to the risk you can afford to take. Everyone's situation and risks are different. I'm sure there are many people that the scenarios I describe above are not applicable. But there are also many people that they are. I have a ton of nuisance wildlife folks that deal with these situation on a daily basis. Hobbyist needs are vastly different than that of professionals.
Bottom line is that having the regulator/bypass on the motor does add risks that are not present when the regulator/bypass is on the catch box. Sounds like these risks are acceptable in your application so that is good, however it does not mean that the risks aren't real.
As always, if it is working for you keep doing it ..... :-)
