This is basically the inverse of some users asking for the ability to link events inside the note. The answer is the same in both case, we on purposely keep the two separate. Reminders can only be used inside the note and are linked to a paragraph of text, while events apply to the entire note only. We don’t want to mix these two as it will add a lot of complexity, both UI-wise (more buttons, more configuration) but also in terms of sheer complexity. Most of all, it would be less obvious what to use when. Should I be using a reminder or an event? Having more possibilities is not necessarily a good thing in that respect.
My workflow is largely based on many small notes, rather than fewer big ones,
I think this already hints at the issue, perhaps you can try a slightly different model. Agenda wasn’t really designed for the “one sentence per note” approach. It won’t scale either in terms of performance, nor does it fit our design choices very well. Mind you, we certainly don’t advocate using single mega-notes, this approach likewise doesn’t fit things well UI and performance wise. But in this sense, the guide to use a single event per note works well (not coincidentally why we picked the event-links-to-whole-note rule). In other words, a single meeting would usually translate to a single note, unless such a meeting would for example be compromised out of 2 or 3 clear or unrelated sections. And on the other side, if you say have a day of related meetings where each would only have one or two notes as the result, you could have those in a single note.
In terms of content per note, you’d probably want to aim at a few paragraphs of text minimally and not more than a page worth before starting splitting it in separate topic notes. The sample documents should give a good idea of the kind of ranges of content you’d normally want to aim for.