It probably has to be handled differently between USB and I2C interfaces.
I2C interface is connected to the device so it makes sense to integrate it with the LimeSDR plugins
USB interface is autonomous and is serial over USB actually so it can be handled independently a bit like he AMBE interface. It can be handled in a specific dialog connected to the Preferences top bar sub-menu. Interface can be quite similar to the LimeSuite GUI one. A possibility to connect some Tx device set activation to Tx control of RFE could be considered.
This is to support LimeRFE control from the LimeSDR plugins.