Nice list! I like many of these "microfeatures" too. Some I have on my site ( https://evalapply.org ), some I don't because I don't want to require Javascript for blog functionality. I think I have a few others not in that list. This is my set of "microfeatures", which are all available in the post I linked below [1]. - All posts must have title, summary, dates (published, updated), one tag at least, and hot link to…
Do you prefer footnotes over sidenotes? And do you think each post/article should have footnotes?
Sidenotes are cool, but they are a skeuomorphism not amenable to fluid layouts. I feel plain vanilla in-line disclosure elements work better, and they might be better for accessibility too.
In dead tree books, I enjoy both. Marginalia can elevate the text. Footnotes are always in context of the whole page, which I can view all at once. No scrolling needed.