You get my vote.
I think a centralized “notes” page would be the simplest approach (and the easiest to implement).
It would also consolidate where “notes” are taken. Currently, I use ZFS bookmarks and ZFS comments to create notes.
To have a “centralized notes page” in the GUI wouldn’t mean I would stop using the aforementioned bookmarks and comments, but it would definitely be the premier place to store notes about the pools, configurations, tweaks, caveats, custom scripts, reminders, and so on.