@George Yes and re. Koto almost immediately (literally days into prototyping) it was decided EFL wasn't the choice and GTK4 was my preference for Koto. Every blog post after that has all been about GTK4. You can see that from all the Koto development streams, including the first ones. Maintaining prototypes when a technical decision has been made on one specific choice wouldn't make much sense or be reasonable in terms of time. There are plenty of other things I can prototype in EFL to get a good sense of its strong suits.
The Budgie 11 post is from 2017. It isn't remotely representative of anything we are doing with Budgie. Bryan and I have, time and time again, mentioned that it isn't going to be Qt5 and the decision was basically retracted practically as soon as that Qt5 implementation started and there was several realizations about the state of the Qt compositor at the time (not to mention the sub-optimal language choice). While it wouldn't be trivial to stylize EFL applications (the issues with it having its own small alternative to the likes of GLib is hardly an issue), GNOME isn't exactly making that easy going forward into GTK5 either, and there is going to be a growing inconsistency in applications that will likely require more homegrown alternatives.