what you said is not necessarily correct. they could render the opengl scene into a texture and send it over to webGL. they never mentioned that they don't sup

what you said is not necessarily correct. they could render the opengl scene into a texture and send it over to webGL. they never mentioned that they don't support opengl 4.5 with this webgl backend, so I guess they achieved it by rendering the opengl 4.5 context into a texture map and send that texture map content to web. but this is just a guess.