Comment by sneak

You can do this yourself in userspace if you really want it:

https://git.eeqj.de/sneak/attrsum

I use zfs where I can (it has content checksums) but it sucks bad on macOS, so I wrote attrsum. It keeps the file content checksum in an xattr (which APFS (and ext3/4) supports).

I use it to protect my photo library on a huge external SSD formatted with APFS (encrypted, natch) because I need to mount it on a mac laptop for Lightroom.