Typical ego driven puffering... This entire conversation started because of a misidentified piece of hardware (no it wasn't a UPS) and the point was there are some circumstances, albeit limited where it may make sense.. I am not going to presume I know all of the details of the environments you've deployed hardware in, big or small, and you don't know the specifics of every miner who has ever deployed hardware..
Don't be so presumptuous..
Well, I do know a lot about hardware and I can recognize real technical problems from the cargo-cult and voodoo-chicken-blood inspired pseudo-solutions.
You would however have to check first that it is acceptable to have the Controller Board powered and the Hash Boards not? For instance Bitmains latest S5+ & S7 both require that the Hash Boards are powered before the Controller Board is fired up. It's all to easy to pontificate using generalities when we are not in possession of the detail.

Rich
I wouldn't be surprised if the engineering staff at that Chinese company doesn't have a real engineering degree but some sort of "work experience" degree after serving in one of those remote technical help call centers.
Edit:
https://en.wikipedia.org/wiki/Latch-up is something discussed in every electronic engineering course and any competent student would know how to deal with and avoid this problem.
End edit.
It is very easy for me to pontificate here because I have all the experience required:
1) I helped many very non-technical artists help set up and maintain their "render farm" which is the finishing stage of ray tracing in computer animation.
2) I worked for many years in hardware design and I know how to recognize common hardware faults and properly fix them.
The "home mining" market is based on pandering to the lowest common denominators of the users, the ones who even have to be explained where on the wall they have to plug in their device.
I had a good fortune on having worked with non-technical people in other markets (animation artists and medical doctors) where such pandering is neither expected nor provided. I really do know what kind of technical work can be expected from people without technical education but with common sense and self-respect.