well found this about reverse dns
Hi.
Well I did a search and I found this answer on the subject. It seems you only need one PTR record for the origin server/ root domain?
https://serverfault.com/questions/1065964/reverse-dns-for-multiple-subdomains
Also here is some more information I found about reverse DNS on the subject that explain the technical side of it further.
https://simpledns.plus/kb/153/what-is-reverse-dns-and-do-i-need-it
–AND–
https://simpledns.plus/kb/77/how-to-sub-delegate-a-reverse-zone-ipv4
Maybe it helps you a bit?
