1)
If HW setup for telemetry via VCP and not USB, when plugging in, GCS see and connects to USB but of course doesn't work. It is required that the user then hit Disconnect, wait about 10 seconds, then Connect to COM port.
If USB telemetry is Disabled, the USB device should not be connected to or even exposed if possible. At the very least, don't connect to it as it is not usable. My wild guess about something I don't know is the problem has to do with the USB must be published in some manner so that the VCP can work. Perhaps not as the HID device that GCS wants to connect to when it see.
2)
Repeat the above steps so that one is getting telemetry over the connected COM port to the GCS. Unplugging the USB cable crashes LibrePilot GCS.
3)
When connected via COM, Setup Wizard will not let one progress past the Board ID step (see attachment). The Next button is never enabled. Disconnecting, reconnecting, Back the Next, nothing will enable Next even when the ID info is all correct.