As long as flrig/fldigi is accessing the transceiver, the only thing you need is a setting that use the correct CAT command.
* If the TX0; command is sent toTS-480, then the transceiver will go on TX using the front MIC input.
* If the TX1; command is sent toTS-480, then the transceiver will go on TX using the rear DATA input.
No other menu setting on TS-480 will select the input, just the CAT command.
It depends on what CAT method you are using.
1. If you are using rigcat, the TX1; command is already configured to be used in the xml file ( http://www.w1hkj.com/files/xmls/kenwood/ ) so there is nothing to set.
<COMMAND>
<SYMBOL>PTTON</SYMBOL>
<SIZE>4</SIZE>
<STRING>TX1;</STRING>
</COMMAND>