It appears that the RTF headers in the Notes are handled differently than the Commentary files in v10, creating a NOTX includes an RTF header, the CMTX supplies its own header.
I agree this would be helpful - but Josh told me that there is a reason Rick decided to treat the RTF differently. I don't know what that reason is but, it is what it is.
What you're really getting at is: you can't have multiple RTF headers in the same database record. And that also means you cannot have overlapping verses IF your verse records each have their own RTF header. Because if you do, that's the same as putting multiple RTF headers in the same record, since e-Sword combines overlapping verse comments into the edit control for display. You used to be able to "get away" with it because of the lax enforcement of the RTF standard by the old edit control. The newer edit control enforces the proper RTF syntax a little better.