Freezing the lesson checkpoints while letting main keep moving is the decision I admire most here — it protects the reader who arrives next year from comparing beginner code with a v3.7 game they never built. I also liked that you named the non-Rust contributions as real ones: docs, keyboard testing, accessibility. Too many open-source invitations say “everyone welcome” and then only reward code. And the story about the first PR landing before the article even went out is the best proof the invitation works — people were already reading the tests as the specification. Good luck with the offline-progress cap discussion; that question about who owns the rule is exactly the right first disagreement to have in public.