[...] The reason is that extended attributes have an (undocumented) size limit [...]
Ah OK, that makes sense. What is the size limit, out of interest?
Ehm… the size limit is undocumented :) It’s actually not documented at all, that there is such size limit. I think it is related to the current implementation, using spare space in the inode for extended attributes or similar, so I didn’t do any practical findings, when I played with this.
So, a _random_ undocumented limit..? Nice :-) I probably won't be the first (nor the last), but I forwarded a bug report to Apple via their feedback form.
Thanks for getting back to me.
-- Nick