Thanks for your post @crabby and welcome to our Community Forums.
We can set a rDNS to either the default setting of username.plus.com, static IP.plus.com or a domain name. For the third option, you'll need to create the A record first and we may ask for proof you own the domain.
Can you drop me a private message with your account username and which option you'd want your rDNS setting as?
From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.