It seems somewhat intuitive that Frames can be composable. 

You can build a frame that can take state data via a POST request and other frames can hook into. 

e.g. a Checkout frame that has an in-frame flow for getting user shipping data and processing a transaction and then sends the user back to the original frame

Cofounder @curated | Builder and Fine JPEG Collector | Mint a meme by casting frameme.xyz

Not sure if anyone's explored this, but personally digging in. Wondering if anyone's created any examples.

me at @unofficial — building the company around this!