Cool progress! Thank you.
I will have to say I find it a bit annoying that there is now yet another place to manage metadata in some almost-but-not-quite-like-the-others format.
AFAICS some random project may have bits and pieces of the the same information in various forms in
- a .yaml file
- a .spec file proper
- the .spec file
%descriptionfor chum - a .changes file
- the OBS package name and description
- a OBS
_servicefile - a .pro file
- some other build-specific config file (CMake, autotools etc)
- Openrepos name, description, changelog
- github action/gitlab ci yaml file
- a
.desktopfile (esp. with sailjail) - QML files (e.g. About pages)
- other source files (Qt.application.name etc)
Not a critique for your efforts at all just - you know - annoying. It’s almost as if the old spectacle-yaml-generates-stuff made some sense after all 
Anyway, anyone up for a patch to spectacle to generate the chum .spec metadata from .yaml?