> Multi-level lists, annoyingly, get rendered as code at the deeper levels because of the 4+ spaces from the beginning of the line.

Not so. You just need to be principled with your indentation, adding four spaces or one tab for every level of nesting.

  1. Here is a thing.

      - See, it works.

          Nothing is amiss.

  2.  If you want to align everything…

      -   Then it looks like this.

          Then it doesn’t seem so weird.

(You can leave or remove the two spaces of HN code formatting; zero to three spaces don’t matter.)