Thanks for taking the time to explain your process and results working on Plasma. There are some great discoveries you are mentioning here regarding using Sketch and how to think responsively within the app.
I enjoyed your approach of just getting started with the best tool, in your case Google Docs, to get started with your Design System. I think often people can get too hung up in automation and trying to find that exact perfect solution.
As I was reading, I found myself very curious about your Sass/HMTL build out phase. To me it sounded (I am making an assumption here) that you are consolidating and documenting the codebase amongst your 3 internal projects. Either way, I would be very interested to hear about lessons learned from that process and perhaps your engineering team’s experience working with Plasma.