Hi Zwift,
Please do not try to force companies such as Tacx to adopt a proprietary protocol to use virtual shifting.
Please change virtual shifting to BLE, GATT, FTMS. If you do this, all smart trainers that support this would immediately be able to use virtual shifting.
IndieVelo and QZ app have implemented it. I can use virtual shifting on my Tacx Neo using those apps but for some reason Zwift are trying to restrict take up.