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