Embrace constraints :)

I have linked to another page or perhaps to an Evernote document which is what I used to use for todolists (but their formatting was painful occasionally).

Agreed though, that if they're going to allow notes, the notes should be more full-featured.

You can treat the notes like a simple document. I have lots of leaf nodes that are like big documents, once you get into them they're basically just like a big plain text doc.

(I am co-founder of WorkFlowy)