Reverse DNS for on-Premise domain not working

Target setup:

• We have a /12 CIDR range assigned to AWS, e.g. 10.200.0.0/12
• All other ranges from 10.0.0.0/8 belong to on-premise
• We need to setup Reverse DNS and conditional forward, so that both, AWS and On-Prem, can do Reverse DNS lookups inside each location and cross location
• I am not taking about Reverse DNS for Elastic IPs, but for all servers / resources in AWS (e.g. for Kerberos and others)
• We followed guidance from this fantastic re:invent video: https://youtu.be/_Z5jAs2gvPA?t=1743

Issue 1 - RESOLVED:

• FORWARD rules do not work for us
• No matter what FORWARD rule I setup to On-Premise, it always resolve to the Hostname type of IP name ("[ip].eu-central-1.compute.internal")
• This applies also when I set up the most specific FORWARD rule like 33.222.111.10.in-addr.arpa; normal FORWARD Rules like example.on-prem.com DO work Example: sh-5.2$ nslookup 10.111.222.33 33.222.111.10.in-addr.arpa name = ip-10-111-222-33.eu-central-1.compute.internal.
• We would have expected name = hostname.example.on-prem.com.

Issue 2 - OPEN:

• The number of FORWARD Rules seems to be A LOT when using a /12 for AWS
• OPTION A: Having a PHZ for 200.10.in-addr.arpa. works for the 10.200.0.0/16, BUT that would require me to set up 16 PHZ for reverse DNS + a FORWARD Rule for 10.in-addr.arpa. to On-Prem
• OPTION B: Having a PHZ for 10.in-addr.arpa. works for whole AWS environment, BUT that would require me to set up 240 FORWARD rules to On-PREM
• Any guidance on this? https://www.ietf.org/rfc/rfc2317.txt only applies to <256 addresses

Unfortunately the documentation on FORWARD Rules on AWS is rather thin. Any hints for this setup / further read / any guidance? Thanks a lot in advance!