What is the practical maximum number of files within a UIDocument/FileWrapper?

I'm designing a document based app using UIDocument with a custom UT conforming to package that mainly contain a json file and a folder of images.

I've read a couple of articles date from 2010s that the base implementation of UIDocument using FileWrapper to r/w a package has major performance issue when it contains a large number of files(i.e. images). Eventually those apps had to override the UIDocument by manually handle all the w/r and not using the FileWrapper. Considering the file coordination and conflict resolutions etc, could be hard and error proven.

Do you have any recent experience on such issue?

What's the practical maximum number of files/images a package can contain that without blowing the performance?

TX!
What is the practical maximum number of files within a UIDocument/FileWrapper?
 
 
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