Hi Michael,
This for sure hasn't been tested and you won't find anything in CWMS documentation about this. CWMS has its requirements, and as long as those are fulfilled, CWMS should perform as designed.
I am not sure what HLB introduces to the mix, but here you can find the Network requirement for CWMS:
http://www.cisco.com/en/US/docs/collaboration/CWMS/1_5/Planning_Guide_chapter_011.html
Hopefully this can help.
-Dejan