As of now we do not have a single document that goes over the behavior of proxy arp on the firewall. However, here are some links to some discussions that go over some topics.
Currently the firewall should only proxy arp for devices it thinks it is responsible for such as a dnat or sslvpn network.
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!
The LIVEcommunity thanks you for your participation!