F5 ingress and egress traffic using the same interface

This is perfectly valid, there is nothing technically wrong with having egress and ingress traffic using the same interface. There are arguments from a security point of view that you may want to force traffic in a typical North/South deployment but your configuration would certainly work.

Just be aware of bandwidth utilisation as you would be 'hair pinning' connections through an interface. F5 is a TCP proxy so for each connection coming in to the F5, you would have another going out to your pool members. For example, if you have 1000 connections coming into the F5, (without OneConnect) you'll spawn 1000 additional connections to your pool members.