... but that still leaves the question of how to write a file to /var/local... (Essentially, that's what the data.(tar.gz|stgz) files did, but that hole is closed now.
Seems like Amazon has now officially declared war on us.
As foreseeable as that was, it's still a pity that companies keep employing the same idiotic and short-sighted strategy of trying to lock their customers in, instead of providing an open (or at least "openable") environment which allows for open development.
I'll keep my PW shutdown and in Airplane mode until we find some way to crack open the 5.3.0 firmware. (I'll still manually download it and look through it).