It's not a Spine plugin, but I'm playing with JS integration of the Spine-TS (webgl) runtime. It will require more direct C3 JS scripting to control the Spine-TS api. I am using Spine-TS to render to a separate canvas and then capture the canvas and update a sprite with the rendered image each frame.
It's currently working, but with one caveat, every few seconds it stutters (it looks like due to JS Garbage collection, there's another thread about that in the forum asking for help on a solution.)
You will need to use JS to control it, so it will require some C3 JS knowledge. The current template is more of a tech demo and would need a lot of clean up to be used in a game, but's promising to see something work.
Here's an example of it in action in C3 (I'm also enabling the display mesh and display bones options on and off.)