The situation is like this. As long as you work on your Engine Prime database on the computer you won’t have problems with database file size. The issue occurs when you have to export your database on a removable storage device, because you have to format it to FAT32 filesystem and thus you’re dealing with 4GB file size limit for any file present on the removable drive. If you think about it, there is logic in the way Denon imagined this, because, in my opinion, you don’t have to carry all your database on the removable drive, but prepare your music program, export it to the drive to use it in standalone mode, but do not forget that standalone mode is intended as a backup for controller mode with Serato. I know many of us like to use the equipment mainly in standalone mode, but this is our choice and not the intended purpose imagined by Denon. They state this purpose very clear in the MCX8000 description - advanced Serato controller with the ability to perform in standalone mode as a backup.
Also, the Engine software was initially developed especially for MCX8000 and added support also for the former SC series media players.
Whenever you read that you must use FAT32 filesystem on a removable drive, you have to be aware of the 4GB file size limitation, regardless of the equipment manufacturer.