New-Bee Observations

When you say it hangs at boot - do you mean it's hanging when it's
reset to send the code? or when you've saved the code and then reset
the Espruino?

OK, put it another way, when I upload to the Espruino, I first issue a reset() then "upload" my code to the Espruino. The progress bar shows after erasing the chip. Then, after the end of the progress bar completion (100%), sometimes, on the Espruino LEDs, it shows them cycling and other times it does not after which it "hangs" with no communications feedback to the Espruino.
addition ...
I always upload the code and when everything is ok, only then do I issue a save().