The Antenna tuning command for Elecraft KX2/KX3 seems not to be correct. In the INI file the command in the "Elecraft" section is
AntennaTuner=SW20;
but it should be
AntennaTuner=SWT20;
I also added a command to set the data sub mode to "DATA A" which is important e.g. if you had used the data mode before for AFSK or PSK etc.:
ModeUSB_D=MD6;DT0;