I opened several NOTE notefiles and assigned a separate Style to
each. I was able to successfully add test notes randomly to each of them
(chose a scripture reference>right-click>Reference>Add a note to...) and they displayed correct icons UNTIL notefiles were closed and reopened again. Then all notes displayed the last-customized indicator style.
Apparently, after notefiles get closed, L4 only "remembers" the last
customization, which does not necessarily relate to the last notefile
being open.