The rule I am trying to hold to: one note, one idea, and a title that states the idea rather than naming the topic. “tmux is a server, not a wrapper” is a note. “tmux” is a folder pretending to be a note.
The reason is mechanical, not aesthetic. Links are only worth drawing if they connect claims. If a note covers six ideas, every link into it is ambiguous — you cannot tell which of the six the linker meant, so the edge carries almost no information and force-layouts draws you a hairball.
Small notes also fail visibly. A note with nothing linking to it shows up as an isolated dot, which is a much louder signal than a heading buried in a long file.