> In particular, Markdown has a todos (using the same `[ ]`) and just uses indentation for grouping. Came here to mention the same thing. I use a plain text t

> In particular, Markdown has a todos (using the same `[ ]`) and just uses indentation for grouping. Came here to mention the same thing. I use a plain text todo format that is quite similar (thought not nearly so thought out/complete) to the one OP is proposing, but I use indentation for grouping as it's a lot easier for me to visually identify related groups of tasks.