Looking forward to following the journey.
I'm the primary maintainer of an inhouse client-side framework, and have many of the same philosophies. Especially the pluggable, unopinionated and "no suprises". I feel magic is the #1 enemy of a good framework, and if I can't follow a logical path of how things work I'm quickly on to the next.
When starting out I was also very into performance and size of things, but as the framework expands I'm leaning more on making it maintainable than performant. I rarely work on a performance critical project, and the few times I do I have used the "pluggability" of our framework to switch out specific parts of the framework that has held back performance.
Anyway, great project, and like I said looking forward to reading more