I am also interested in this, as it provides really neat features such as live video chat (WebRTC) while working together on a wiki page.
I installed this plugin on 2018-04-22a "Greebo" and it seems to be still functional at first glance, i.e. for the first user seems to be fully functional.
However when I try to edit with a second user (from a separate private Firefox window), all I get is the normal Dokuwiki locked message with no option to start Etherpad.
There is also no error message in the browser console, which lets me guess that this is maybe just a display issue of a "join" button with the newer version's skin? I tried both the Dokuwiki default theme and the "SprintDoc" theme, but the same issue happens.
Is there some way I could debug this? Help really appreciated.
P.S.: I also opened an issue on Github about it:
https://github.com/michael-dev/dokuwikietherpadlite/issues/19