Because why not? It'd still depend on most of the internals of frames, but could be useful as another path to usage.
In a way this would be a variation of the autoInitFrames function. Because it'd already be in the land of "IE isn't gonna like this" it could even interface with IntersectionObserver, perhaps?
I'd like to get a 1.0.0 out the door first with the stuff in rework, but may poke on it afterward.