Filter when using --xattrs?

[Luis Fernando]

Hi! I'm new here, so I ask for your patience :)

Some xattrs can't be copied between filesystems. For instance, compressed btrfs has a "btrfs.compression" xattr.
When rsync -X is used in this situation, it exits with error code 23 (partial file/attr), which seems dangerous to be ignored.

Would it be reasonable to filter filesystem-specific flags when transferring to a different filesystem by default (I'm not sure all fs follows the same namespace, but maybe they start with "filesystem.*"?)? Maybe -XX could be used to force it.

Thanks,
-- Luis Fernando