uploading new js script doesn't kill current running script in RAM. - callbacks not called even if function completes

Not sure if this would work but can you try putting the wifi.on stuff outside of the connect function? (I'm assuming this is what you were referring to as the callback)

Actually nvm, consider me confused which callback you're referring to :D I saw an emit somewhere and I'm not sure what's happening anymore.

I personally just do simple things like the ones found here: https://www.espruino.com/ESP32#connectin­g-to-wifi

Maybe try this one first and see if the wifi.connect callback runs? (again, I'm not really sure which callback you're referring to).