If the RF that it is detecting is only WiFi then I suspect the Librem 5’s WiFi module should be capable of becoming promiscuous, as it were.
There is plenty of RF that is not WiFi however e.g. Bluetooth, cellular, ISM, LoRa, …
I think there is no general IR transmitter or receiver as such in the Librem 5 (which is a pity because it could be cool to be able to use the Librem 5 as a remote control) although I think the proximity sensor is an IR transmitter / receiver of sorts. Maybe you could get an IR transmitter / receiver USB dongle. 