Attempting to launch a Groupy with any OneNote windows results in only one OneNote window being loaded and it is that of the most recently opened OneNote page.
I've recently discovered how to launch multiple instances of OneNote, and have each instance get a particular page:
Essentially you have to launch the ONENOTE.EXE from the command line or batch file, and subsequently launch the ONENOTE.EXE again with the /hyperlink switch specifying the Notebook\Section\Page. The most recently launched instance of ONENOTE.EXE will navigate to that location. The problem is one of timing. I can't attempt to launch them all simultaneously. There needs to be a brief pause between launches of the instances. I'm able to do that in a batch script:
REM start the program
START "MyWindowName" "C:\Program Files\Microsoft Office\root\Office16\ONENOTE.EXE"
REM wait for 8 seconds for program to load before attempting to load page.
REM This allows for whatever cleanup OneNote does
timeout /t 8 /nobreak
REM load the page
REM hyperlink argument requires path be URI encoded
START "" "C:\Program Files\Microsoft Office\root\Office16\ONENOTE.EXE"
/hyperlink "onenote:///C:\Notebooks\MyNotebook1\Section.one§ion-id={MD5}&page-id={MD5}&end"
But I could not get it working in the Groupy file format. The only improvement I'd been able to make there was having the single instance point to a specific page. But attempting multiple instances fails.
I'm looking for more information on the make up of the Groupy file format.
And of course if there could be some time and consideration put into supporting OneNote as you do the peculiarities of Word and Excel 
Thanks!
