Mike 
In manual page 28 Advanced Settings it says K3 uses Yaesu settings F2000/5000/9000.  Your note says use Kenwood IF?  Please clarify.
Also I cannot find in the manual how to set the WebSwitch 1216H to interface with the RRC Remote box 1258 .  Is it required to interface to read the frequency of the radio?.  The WebSwitch does not have RADIO-RRC Settings page.  
I have port forwarded UDP port 13010 to the IP address of the WebSwitch and also have Automatic Control ON.  Also have set frequency range for two relays  80MSSB and 60M .  When I tune to those frequencies I cannot see any thing happen with the relays.
Also in 1258  Remote Box STATUS page ANTENNA-SWITCH IP = Not Connected.
I need a bit more info on how to setup.  Thank you.
73 Frank VO1HP