I only suggested muting the receiver because I have several rigs on an ANT switches. When I fire up the 813 rig I peg the S meter on the FT102 so I disconnect it because I have no way to mute the receive section but my stand alone receivers I mute to protect as much as possible even though the ANT switch is a shorting type. There's enough RF in the system to get to the receivers.
I figure even with 100 dB isolation, you will still get a few mV of signal into the unselected rig. In my case, the unselected rig will always be off, so no problem.
Bobby Dipole ND9B