If you ask me, btrfs had issues in the past and it caused them some reputation damage but it's getting there. And many distros started using it as their default

If you ask me, btrfs had issues in the past and it caused them some reputation damage but it's getting there. And many distros started using it as their default, as does Synology. It's a safe pick if you ask me. Still, I would go for ext4 if you don't specifically want or need things like storage pools, snapshots and such advanced (ZFS-like) features.