I want to set up an app_rpt server with two independently functioning simpleusb nodes: 

Node 1. Full duplex repeater 

Node 2. Aux transmitter

The second node is nothing more than a transmitter (TX audio, PTT) so couldn't I simply configure the second node's simpleusb.conf file with "gpio4 = ptt" ,  "txmixa=no", and "txmixb=voice" ? 
Thanks and 73