These are some great tips! I have some notes:

- One of the things about design you notice as you get older, is the bigger a software application is, the worse your options are later on. The design doc can be considered a proxy for the application: the bigger your design doc, the bigger the application will be. You should still try to think about as much of the app as you can in your design doc (don't intentionally try to make it small and miss things). But if you start to notice this doc is getting pretty heavy, that may be a hint that the application is trying to do too much.

- Next suggestion: make C4 diagrams and split up your design doc by each level. You don't need to make perfect C4s, or even have a good handle on how to define them. You just need four levels of abstraction by which you'll give the reader a picture of how your application works and fits into larger concepts. This will help you and the reviewers understand it better, and will likely also elicit more questions, which helps you better define the design.

Example C4 layout:

  SLAs & SLOs
    - Interfaces & Logging
      - Monitoring, Alerting
      - Dependencies
    - Security / Privacy / Legal
    - Infrastructure

This is not levels of abstraction, it's a dependency graph.