I used it to help build this 2 bay, circularly polarized 450 MHz antenna. Each bay tuned for frequency and impedance. 75 ohm matching stubs tuned. And then the final tweaking of the two paralleled 100 ohm bays to get a 49.7 ohm resonant antenna at 450 MHz.
The NanoVNA was invaluable for each step of the process.
Now on to pattern testing. It should give me 0 dB gain and be unaffected by the polarization of the distant reference antenna. We shall see.............
WA8TOD