Hi!I have two companion apps, iOS and macOS, supporting iCloud Drive to sync files between devices.Both apps are operating on 3rd party file formats, which are - under certain conditions - enhanced with additional information. This metadata is currently saved in "extended file attributes" by using setxattr / getxattr .Unfortunately I realized that the corresponding file attribute is stripped during iCloud synching. Changing the originally individual attribute name to "com.apple.ResourceFork" was unsuccessful, too. Some attribute seem to get synched, but I don't want to hijack attributes with other purposes, which will lead to unwanted side effects.What is a supported way to store metadata with a 3rd party file format for iCloud syncing, when a file-wrapper is no option?Greetings, Matthias