Hi Aaron,
I finally got a lab environment running with an ICAP server in common and route domain 0, with my virtual, HTTP Class and Policy in a second partition and route domain with strict isolation turned on in both. It works well.
Hopefully today I will have a new VLAN at my disposal to attempt this in my test environment (identical to the target environment) which I will configure in the common partition. I'll configure a virtual in common to load balance the two ICAP servers in this new VLAN and expect to see a much better result.
I have also opened a case but no response yet.
I'll let the community know the result of both the case and my configuration.
Thanks
J