It's been on my radar for a long time and I have prototypes for one that are bitrotting on gitlab. There are three major design pieces of it.

First, It has an executable that runs in your development container (environment/etc) which means you can load libraries/typelibs/girs/etc just like the app would without crashing the IDE (or Glade in the old days).

Second, everything is an AST node so doing fun manipulations, unlimited undo, etc is just tree mutations.

Third the worker process does the rendering to a render node tree which is then shipped over to the Designer process to render.

The cambalache author and I are friends, so we occasionally talk about how we can make things work to integrate from Builder.

As for blueprint, that is outside of my knowledge area. I still do everything in XML and would prefer a designer to work with trees anyyway. Not sure I'd go the route of mutating a blueprint AST, but I hear it has back-and-fro to XML so that would probably be fine.

Also, if you want to make this a higher priority, lobby my employer (Red Hat) to make sure they know it's important to you.

Secondly, help me with _any_ of my other projects so I have some cycles to dedicate to it. People rarely notice but Builder, Sysprof, Text Editor, D-Spy, Manuals, Ptyxis, etc... are all one-man (split between many) projects and libraries.

If you are talking about "drafting" I even had a few contributions in 2021. Would love to see it evolve.