Day by day, my notes are getting bigger and bigger and there are some contents that I do not intend to change, simply because they are study notes. So the feature of being able to block some notes would be a really nice one to have.
I suggest that just in case the person needs to unlock for some reason, the block feature could be a note status, where the user would have to use a toggle button to lock/unlock and have a popup message showing up to make sure the user really wants to proceed with th action whethe it's locking/unlocking the note. In case it's locked, the edit button would stop appearing.
Hope I didn't complicate this idea of locking lol.