As I understand it Lightroom 6 for Mac won't compress a catalog over 4GB. This is quite frustrating. I understand that the native Mac compressor can't un-compress these larger files, but many programs can. It would be much appreciate if while backing up a catalog Adobe made compression for catalogs 4GB or more an option on the Mac. I have the software to de-compress these large zip files, but it is a pain to do a manual zip every backup. Since I have a large catalog it seems I would benefit even more from this automatic compression. Perhaps a toggle box (default turned off) could be added to catalog settings with a disclaimer stating "third party software will be required to unzip large files". Please, please, please consider this. Thanks!