Fantastic post! I’ve been dabbling with similar concepts around base-lining typography, using it as a foundation for vertical rhythm and spacing conventions in design systems.
The depth of your work is remarkable. As a front-end developer I always seek better ways for communication between designers and developers. I also like to make systems that makes work more efficient. Your approach is pure gold.
Hopefully, my designer colleagues will find this systematic approach as liberating as me. I still have a feeling that many designers create their perfect comps based on feelings (they really put their heart into it :-)), and not always by rationale and logic. I guess it’s a time and place for both. Still, I think your approach really nails it when it comes to effectively communication aspects of design. It helps collaboration a lot.
Any tips on handling typography in a responsive context? I always need to scale down the larger font-sizes for smaller screens to avoid longer strings breaking up. I find the hard part is to do this in a way that also consists with the overall baseline system in a rhythmic manner.
Anyway — keep posting. This is great!