As many others Kenwood TS-2000 users I was trying to find a solution to reduce the number of cables between transceiver and PC. Audio i/O, FTDI for ACC2 PTT, serial for CAT.
If the TS-2000 had the option to select the audio input (front/ACC2) or if the CAT&audio was on USB bus it would be OK, but it's an old rig so this is what we have, Of course, there are of the shelf solution like Signalink or others audio and CAT interfaces, but this are also expensive (for me anyway).
 After a while I came across a site where is presented a theoretical solution used for repeaters: a cheap (under $10) USB audio interface with a "Mic Mute" LED.
Now, I would like ask the WSJT*X savvy's  or developers: how hard would be to implement/add  a "radio button" for "MIC Mute" PTT in the radio PTT section from settings?
If this would be possible, the hardware implementation would be the easiest solution I can imagine. An optocoupler or a small reed relay acting as PTT when the 'Mute" is active.  After all, we don't need the mic input when the transceiver is TX-ing.
The solution wold be a simple one even for older rigs with a little tinkering.

So, Is there a possibility to add a "Mute" button for PTT?
73, YO8BCA