Any pitfalls or issues I might encounter backing up a FreeBSD 12 PC to a Btrfs path on a Debian 10 server?

I have a FreeBSD 12 PC whose OS lives on a ZFS zpool. I’d like to use urBackup to back this up to a Btrfs raid1 subvolume on a Debian 10 server. Any caveats or issues I’d need to look out for?

what do you use to backup… rsync?.. In my config … the /urbackup Data-directory explode in size … example 200GB in zfs are 0,9 TB on btrfs…