Hi Michael!
I think it is a good idea… but I’m wondering how well it work as a broad brush feature given the constraints of the Internet - in particular the part about the timelines running (smoothly!) during the transition. I already have issues getting individual scenes to load quickly with designs that involve video, many large images, or lots of small-medium animated images.
The approach I have taken is to do the transition from Scene A to Scene B entirely in Scene A then do an instant transition to Scene B (could run it the other way, A jumps to B where the transition is done). The important thing of course is to find the right spot to make the jump where it won’t be noticed - and so I design things accordingly.
Web design is a series of compromises. I found this one serviceable enough for my needs - not to say it would be a solution for every situation.
Original Transition below by @josefrichter here - I’ve added minor adaptions.