I’m using a work around for now.
I use text expander to drop the following in the first line of each note when code typed:
SDS: %snippet: mydate%|%snippet: mytime%
this results in:
SDS: 20180629|225151
I use this system across all parts of my “Schedule-Diary-[notes]_System” … copy/paste from one app to another allows me to track between otherwise unconnected apps. in long docs I will embed at critical points so I have a “finer grained” universal index.
This is simpler (and more fine grained in single user system) that the complex UUID approach.
Of course I much prefer a well defined URL scheme (with x-callback functionality) but find the process described above as a useful hack.