That is correct. You can learn more about that system here:
I can understand the confusion, but what you’re asking us to do has no relation to what they ask you to do.
What they ask you to do is for us to make an exception to our bot protection system that allows access. And instead of just giving a list of IPs, they want us to check for every incoming IP whether it’s theirs based on the reverse DNS of that IP.
In other words, our servers should lookup their IPs via rDNS. This has nothing to do with the IP address of your website or the rDNS entry of that IP.
It seems pretty clear to me that this specific plugin or functionality cannot be used with our hosting. Perhaps look for a different way to improve your website’s performance?
Note that there are many different ways to improve “performance”, each with their pros and cons, and with impact on different aspects of your website performance.
Also, if a website is slow that’s often the result of having too much “stuff” going on in it. If that’s the problem, then adding more things may not make things better.