I know the Xm+ receiver does not have telemetry but does it at least give rssi warnings back to the radio?

No, but you can set it up so that you have RSSI on an OSD (if you have an OSD),
Or you can pass RSSI through a spare PPM/SBUS channel back to your TX, and setup a logical switch to warn you when RSSI drop below a certain value?


As far as I know, the XM+ is a receiver only. It is not capable of transmitting signals back to the transmitter. Therefore, the transmitter cannot see how much signal strength the receiver has. Conversely, the FRSky telemetry receivers (like X4R and XSR) are actually transceivers. They ARE capable of sending information back to the transmitter, including RSSI.