So, it’d be useful to be able to quick add a tag. This would solve the pain of remembering the whole day at 9pm.

E.g. I eat fast food, I open Exist (or use a long press shortcut on the icon) to quick add a “fast food” tag for the current day. Later on in the day I tag other stuff in bulk and the fast food tag is already there in the field.

This would also allow quickly adding a forgotten tag to a day. E.g. after doing daily review suddenly remember that “running” was part of the day, quick add that tag (rather than going through the whole daily review pipeline)