I would hesitate to put a longer antenna on the tinysa or nanovna from a mechanical point of view - it will put a lot of strain on the sma and could ultimately break the connector from the pcb.
What I have tried is using my RTL-SDR antenna which has a soft cable link from the SMA to the antenna. So at least less strain but it is unwieldy. And that is a dipole antenna so I am also having to read up on what effect that has.
