Updating the firmware without a smartphone

@Gordon, I like that... even though it is slower, may be unreliable / a tad less stable (?), it is better integrated: Espruno https://www.espruino.com/ide/ Web App, the one stop shop for everything Espruino. It is inline with most recent flasher additions and - foremost - inline with your original motivation to go onto the pursuit of Espruino in the first place.