Yes. While not a best practice, it is a common set up.
Does it have any advantage to do so compared to using BTRFS instead?
Depends on what you are running.
ZFS is not bundled with the Linux kernel but supported by some Linux distributions.
BTRFS is bundled with the Linux kernel but not supported on non Linux platforms (BSDs, Solaris,...) although there is a Windows reimplementation.
ZFS supports ditto blocks (copies) giving some protection against media partial corruption. Here is a page describing some ZFS advantages against BTRFS.
Yes. While not a best practice, it is a common set up.
Depends on what you are running.
ZFS is not bundled with the Linux kernel but supported by some Linux distributions.
BTRFS is bundled with the Linux kernel but not supported on non Linux platforms (BSDs, Solaris,...) although there is a Windows reimplementation.
ZFS supports ditto blocks (copies) giving some protection against media partial corruption. Here is a page describing some ZFS advantages against BTRFS.