After trying 18 different external WiFi dongles, we have found that one (of the 18) works with minimal headache. It’s the “BrosTrend AXE5400 Tri-Band USB WiFi Adapter”. Its uses a Realtek WiFi 6E chipset and the BrosTrend driver works out of the box - sort of - just run (sh -c ‘wget https://brostrend.com -O /tmp/install && sh /tmp/install’), wait until that all completes, and then reboot, and your WiFi setting tab will show the second WiFi (as a new tab on the top). You may have to mess with `nmcli` to turn things on. We generally see a performance improvement over the internal WiFi, presumably due to better antenna placement / geometry - you can put the USB WiFi on the head of the robot for example which gives you better omnidirectional performance. The tx-power is also 16mW (just like the internal dev kit WiFi) but higher dBm antennas seems more important than tx-power.
Hope this is useful,
Jan