Local notes for recurring calendar appointments

When I create meetings, the appointments in my calendar come from another user. That is usually no problem, as I just need to know when an appointment is. The note has info by the online meeting software in it (URL, connection numbers, the whole spiel).

I want to add a link to a Things tag for an appointment, so I can pull up todos for the meeting quickly. (I go to the calendar appointment to get the connection URL anyway, so a link to the tasks would be useful.)

I see that BusyCal has a “My notes field” (that looks like it does not get synced, so is pretty useless to me). Theoretically, Agenda would be the way to go, but the notes are attached to individual entries instead of one note for all recurring meetings.

I’m mostly on a Mac when I need it, but sometimes, I’m not. A solution that works cross-platform would be much appreciated (but not strictly necessary).

Has anyone else that use case? And if so, how do you solve it?