I have a similar issue with Notion 6. I would like to be able to create a default score sheet that is A4 page size (i.e., the page size used throughout Europe) and the fonts are Arial, not Baskerville. My only instrument is piano and all of my scores are for piano.
Currently, every time I want to create a new score sheet in Notion 6 (or Notion iOS) I have to select 'Piano' in Full Score Setup, then I have go to Full Score Options and select page size A4, Arial fonts, etc. It would be great to have an option of creating a user default template rather than having to recreate the same thing every time I create a new score.