There is one fool-proof PTT method and that uses SDC. You do not need anything special. It allows many PTT actions for various devices that need it. It cannot fail because it emulates a COM port action, either CAT or PTT, driven by TCI from the transceiver. If the radio is going into TX, the PTT must activate.
You need a USB COM port adapter with FTDI driver, a two-wire cable (ground and either the DTR or RTS pin) to the plug for the transverter PTT input (usually RCA), and you need SDC version 12.20 or later.
On the TCI tab, initiate Rig Emulator, set it for PTT and assign it the COM port number created by the USB COM and configure the port as required.