I got skiddish about my data integrity when I tried updating the email address associated with my icloud; my notes stopped syncing from my iphone to my macbook etc so I decided I would export everything for a backup lest a "sync" operation decide to wipe my data from the blank device to the one with data.

I was frustrated for hours trying to find the export option in notes (there are some half-measures) but in the end I was pleased with the file format they give you when you download data from this page, equivelant to google Takeout:

https://privacy.apple.com/account

It does take a few days from the request to the zip download, but I got my 100GB of apple photos and 5,000 apple notes complete with pdf and url attachments