Attach notes to combinators, entities... almost everything
+ Adds signposts.
All notes are saved when you export a blueprint as a string (but you need the mod to read them).
When I create a blueprint with trains in it, the schedule of the trains are not saved when the mod is active. When I disabled it, the schedule was saved.
This seems to be a factorio bug. I reported it here: https://forums.factorio.com/viewtopic.php?f=7&t=71614