My question to anyone who knows the answer: would it be possible to write an app (in Linux of course) which access the /dev/tty.FORESP8266 and writes/reads raw blocks, such that it could be bundled into AppImage and run on, basically, OSX and Windows as a Linux app - and still have the raw i/o access it needs to perform a firmware update?
If so, I'm willing to expend the time to learn how to use it and build this app .. it seems to me to be a more interesting approach than using, for example, Qt to build a cross-platform serial i/o app ..