dust and humidity are more damaging then voltage issues.

I meant to ask  are you running a lot of s15's or mostly m10's

We had the one report of some dead s15 psu's running in the 240-245 volt range

2 maybe 3 on this site.
I am mostly m10's myself no psu issues.

I know you run lots of gear I wondered if you have tested enough s15's to form an opinion on them.

The suggestion is dont waste the money because it will do nothing for you.

The PSU IS the voltage regulator for the miner. That is why they have a variable input range but always output a stable voltage. Whether you feed a PSU 210v or 240v, the DC output will still be the same.

You should double and triple check what you hear, especially on the internet, because whoever told you that is pretty clueless.

What kills ASICs is poor environmental management 99 times out of 100