Thanks Mojca.
If you are lucky, it puts the files where you want them to be, but since every installation works its own way, it's hard to predict where to put them; ... Of course you can. But if you happen to update TL package, your additions will be destroyed. And you need to rebuild all the other formats. It's not so harmful.
Supposed to relates to "your system would be supposed to update its own packages", but for ConTeXt it obviously doesn't do. ... If you destroy (overwrite) the old binary :) - if you dowload the wrong binary, then you have neither working. Generally, it should work OK.
Caramba! Tricky, tricky stuff. FYI, http://wiki.contextgarden.net/Installation_hints mentions, under the "Updating" paragraph, (after calling ctxtools --updatecontext) "then you have to regenerate the format(s)...", while you wrote
All it does is: - download the zip - unzip it - make the formats
I wonder, for the record, ... Is there any (installation) process which enables ctxtools to update ConTeXt without risking to #@!&X% it up ? Side-question: "But if you happen to update TL package" - what does TL stand for ? Best, Alan