Can we use a UPS instead of an stabilizer?
Google "UPS Transfer time" and "PSU hold-up time".
What happens is that the PSU very briefly shuts down then restarts causing the miner to reboot. Pretty much ALL standby UPS's have transfer times that are too long for mining use which is why the dual-conversion ones are best - BUT - being always on-line you do take a little efficiency hit.
You can use the same types designed for large computer servers (eg: Blade).
In My Opinion an UPS is a bit overkill, and you need to replace the batteries every two years or three, adding to maintenance costs. An UPS simply switches to battery when something weird goes with the mains, while the "voltage regulator" tries to compensate the problem by itself. And yes like you say, they have response times as well so depending on the problem it might not prevent a reset.
Ideally the PSU is great and can tolerate a lot, but worst case they test it for China mains which is 230v @50hz like Europe.
Here protection would be the first goal, not so much a reset. Ie, don't let a voltage that would harm the PSU in. Second would be stabilize the voltage so input can fluctuate but output remains stable. Ie a low tolerance PSU that could burn with a 250v peak.
Of course a simple (cheaper) air conditioner/refrigerator protector could do the same, at the expense of more resets. If you have a large operation, make sure they have adjustable timers, to prevent them all going and coming at the same time...
A decent PSU should not let harmful DC voltages even when getting weird things from the mains... Someone would need to review and stress-test those new Bitmain PSUs to have a definitive answer. How much can they tolerate, how stable is their DC output regardless of input? Etc.