That's fair, and I agree it would be much better if it was officially supported. I'm on a rolling release distro but I had to freeze all my GNOME packages to stay on 38 because of the issue you mention.
But I chose GNOME knowing they have a tendency to break a lot of extensions with new versions, which is honestly quite a pain and something I understand many (if not most!) don't want to deal with.
That would be OK for some minor adjustments, when user can live without this extension for a while. But for something as major as dash-to-panel, it should be official and updated synchronously with main project to be a proper option IMO. That's my reason to avoid this extension for now. It might be good, but I don't want to depend on it.