ZC 3.0 From Scratch Plan

[Gleeok]

I'll just go ahead and throw this out there, but taking something like the tiled map editor and stripping it down and using it a base for an editor might be a really good option as well. In fact I'd probably be down for using that as a map editor for FFC as well.

http://www.mapeditor.org/

Is there any advantage to writing a core framework?

Knowledge and experience, and . ...perhaps also eliminating massive bloat and dependencies from 3rd party libs, or just having to learn new APIs or dig through documentation constantly.
Aside from that if you are trying to actually get a game done then it's dumb, like I said; simply because it is a time-sink and time spent on that is time away from other, possibly more important, things.

[ZoriaRPG]

Showing the love.

Anyhow Gleeok, you may want to look at what Solarus has to offer. It's all on GitHub, fully open, including the actual games. Try the editor too, at least, for it may give you ideas.

As I mentioned, if the team here could add ZC features into it, make a back-compat mode possible, at least for ZScript, and possibly the present .qst model (converting?), that would be ZC 3.0 in a nutshell, and might save another ten years of work.