I would be interested in this too, H5P core vs plugin, the library plugins, version conflicts etc, have been causing some issues for us lately.
I can also add to this that our own subtheme allows you to change the CSS inside H5P elements, which might also be of interest to some.
I can also add to this that our own subtheme allows you to change the CSS inside H5P elements, which might also be of interest to some.