Interesting article about the supported filesystems of the dropbox desktop clients. From november on only Ext4 for Linux, NTFS for Windows, and HFS+ or APFS for Mac will be supported, the main issue being the need for xattr extended FS attributes:
For sure it’s much easier to remain in control of only 3 filesystems - from a dev’s view of course. But as the article mentions, other filesystems do also have xattr. Strange, but we don’t care.