Ok, SO just got some test results back from Warren.
Look like the bare PCB has excellent isolation between input and output, 90db.
I think matches with RF rated relays and separate in/out relays this board will perform very well:
Here is an updated pic, a few tweaks, more ground stitching.
Only downside is the $1.50 relays (x8)
reuse K3(or not) or get an AXICOM relay.
Maybe Ill just change to using omron G6 in the TX/RX relay too..
Buy 10 on ebay and have a spare?
74 NIck VK4PP