As part of investigation of radio remote options for the NanoVNA, a 3D Robotics (SiK) clone radio was evaluated. Firmware is v2.2.
Above is the radio. These are widely used for UAVs, indeed the firmware is optimised for that application. My assumption is that the thing implements a reliable radio link, potentially over distances to 1km or so (at 20dBm tx power).
I have used these on UAV applications and the radio comms has been reliable out to a few hundred meters (including ground to ground).
The USB and a non-USB device were configured for 57600 DTE speed.
Above is a test of throughput using Ezurio Terminal with the devices separated 5m.
Since the NanoVNA does not implement flow control, buffer overruns can be expected to occur and this configuration is dismissed.