> "From what I can gather, not with V3 and above. I think starting V4 they will go render-agnostic so they can use Vulkan and Metal."
That would make sense, last time I touched it was back in 2012.
> "Besides, there is more than rendering for a decent engine."
For sure, but Cocos2d-x is a complete software framework and SDL is meant to be a library. Although I would grant that it would make sense if the author would choose to use a game engine for his game.