Hey,
As you already know Billy doesn't have enough time to keep Pl3xMap up to date and therefore handed the project over to the open source community. Since there is no "official" successor, but different forks maintain the project, I can not guarantee for each fork compatibility, because I do not have all on the screen. The version uploaded here is in any case compatible with
https://github.com/NeumimTo/Pl3xMap. On github you can find a version in the release section that is compatible with
https://github.com/jpenilla/squaremap. As long as the forks don't bring significant (api) changes or name changes, the addon should work there too. The next update from my site will probably finally bring custom marker icons per ID. Need to find time for it.
Cheers
Sentix