If you still need an answer to your question, the latest extension version is still 5.2.2.
And for the other one (Edge keeps disabling the extension), that's something related to the Edge app, so the question needs to be asked to someone at Microsoft. But I suspect there's no solution to that, because only extensions coming from the Store are considered "signed".
Anyway, the blog post says
It seems clear to me that the extension will work for everyone only with future versions of Edge, when "official APIs" will allow the kind of communication they need.
Also, take note that Microsoft isn't accepting extensions in the store yet, so even if it was ready, it couldn't be submitted or published.