Strings attached.

If the same fact lives in two notes, sooner or later one of them is wrong and you won’t know which. So when you need it somewhere else, link to the note that has it. If it changes, it changes in one place, and everything pointing at it stays right. Quote a line if you want it in front of you, but keep the link next to it.

Link the notes you mention, name the people involved and tag the threads. Links should work both ways, so opening a person shows every note they’re in, and opening a note shows what links to it.

Over time the links map out your work. You’ll see clusters where you keep coming back to the same ideas, and orphans that never got connected to anything. Check the orphans once a month. Most are either finished and can be archived, or unfinished and need linking to something.