I understand all your listed concerns and annoyances and can see why you’ve EOL’ed it (is that a term?).
Obviously I’m no dev so forgive the n00b question here: can’t you build the Safari extenstion without inclusion in the official gallary, and when necessary notify users of updates as a function of the extension? I seem to remember it working that way long ago.
Regardless, thanks to the team for all the work in the past and for your thorough explanation here.