My firewall/security device is performing a reverse lookup of addresses already resolved by the Edge when making WebRTC calls, is this a supported configuration?

Yes. WebRTC can support this type of configuration, but it is not a practical.

To allow WebRTC to function with this type firewall/security device configuration, you would have to add all domains to your allowlist that the Edge resolves that your firewall/security device considers suspect. Doing so is problematic.

Genesys Cloud best practice specifies:

1. Do not configure your firewall to perform reverse lookups.
2. Do not add domain names to your allowlist.