Any document for the current file type for notes?

[Iey4iej3]

I wonder the structure of the current file type for notes. It looks like a binary data file. I wonder whether it is some standard data file (such as BSON)?

[CodeDoctorDE]

Butterfly uses json files inside a zip directory

[Iey4iej3]

Then is there any performance issue when notes are large (if, say, with frequent autosave)?

[CodeDoctorDE]

I don't see a real performance problem.
The zip structure allows me to save assets inside of the document