Very interesting, IMHO one of Mastodon's biggest advantage is not the reverse-order timeline, but the ability to build your own timeline view, pick your own algorithms. There are already a few frontend-based solutions. This one is another, and quite interesting.

I only wish the (vastly underfunded) Mastodon team would see this as an opportunity to provide server-computed timelines to prevent clients from fetching too much information just to get their own summary.