A lot of questions come up about “how do we back up the metadata drive”? The solution is to stop the file system and perform a "bwmetadump" command or a standard “dd” command so normally this isn’t worth the trouble.
Imagine this scenario: A FAT32 or NTFS HDD in hand. You wouldn’t backup the FAT table of that HDD, and instead would back up the files and folders on it. The conversation with HyperFS is similar, the metadata (FAT) is useless without the data, the data is useless without the FAT, so it is best to backup the files and folders themselves, because that is the data you want saved.
So it can be done with bwmetadump manually but it is best just to back up data normally.