I'm a user of a single user script that I wrote myself, so quite inexperienced with Greasemonkey of any version.
How to add my script was baffling. The blog posts mention that only the built-in editor is available now, not editing files directly on the file-system. So I spent quite some time looking for how to open the built-in editor, or a ‘new user script’ menu entry or similar.
In the process of not finding that, I stumbled upon the ‘Get User Scripts’ menu item. That took me to a page whose first entry says that GitHub's Gist service can be used for hosting user scripts, so I pasted my script in there and went to the raw URL. The raw script was displayed in the browser, but it still wasn't clear what the process should be for getting it into Greasemonkey — I tried dragging the URL icon onto the Greasemonkey icon, and all sorts of things!
I went through the debugging steps on the website and couldn't see anything relevant. Eventually I tried sticking my script on a web server, and discovered that when visiting it Greasemonkey just intercepts the URL and provides an install option. It's all working fine. Thank you!
But it was far from clear from either the ‘user’ or ‘script author’ blog posts that that was what was required — probably cos I'm neither a user of publicly posted scripts nor an author of one, so the whole ‘hosting’ side was new to me.
Seeking help on what was going on led me to this mailing list, and further down this thread somebody linked to a GitHub issue. Learning of the issues list, a quick search revealed the following issue, which explains why Gist no longer works for install:
https://github.com/greasemonkey/greasemonkey/issues/2631
So I think the biggest problem is that the in-app ‘Get User Scripts’ link goes to a page which recommends a service that no longer works.
Best wishes
Smylers