Related to my request about being able to link to callout headings, it would be useful to have callout headings show up in a list. That way, when scanning the outline, one can quickly find the important, info, or summary callout one is looking for.
The callout headings could show up (and maybe stand out in their colour codes?) in the existing document outline, and there might be a button in the outline to show (filter) just ordinary headings or callout headings. Alternatively, there might be a separate callout list with filters for different types of callout.
At the moment, I just scan the outline to guess the right section, then scan the note section to find the callout I am looking for (they stand out, which makes it easier).