The plugin uses very similar technology to the one shown on GDC (they also said they use OpenCV but Chilitags not ArUco).
A multiple marker configuration can be used - markers are placed in the blueprint editor (as actor components). In the GDC demo, they put the markers on the car then scanned them, in this plugin you need to know the position of the markers.
If you are interested in trying the plugin, please let me know. so I can package the current version for you (the last published one is far behind current state of the plugin)