sweet. yeah i knew it was possible... i was working with GUI composition a few years back and i was at a point of merely struggling with the pipeline scheduling, but i built a bunch of neat extra widgets that didn't exist in the toolkit that still haven't been pushed into the upstream and i'd do it if i could get synced up with the state of it but they change the api so much my old code needs yuge amounts of changes to adapt to the new api

it would be simple to add video composition to any competent composition pipeline as a post-step, without adding a lot of complexity to the codebase