Hey, I use TR and Zwift concurrently. I have 1 bluetooth and one ANT+ Dongle. I disabled Bluetooth in TR Settings, so TR always uses the ANT+ Dongle and Zwift uses the BT one. Works flawlessly, I’d recommend starting TR first in this scenario.
I suppose you can use the same approach with RGT instead of Zwift for yourself. Just make sure RGT does not take control of your smart trainer if you want to use TR in ERG mode.
More info here (tailored to Zwift, but again, just interchange RGT for it): https://www.trainerroad.com/forum/t/using-tr-and-zwift-concurrently/