I have a UNAS-Pro, which runs the same Unifi Drive software as this, and it works great for Time Machine backups. Dead simple.
I also have tons of other Ubiquiti gear, and honestly there's not a ton of synergy between the NAS and everything else. It's a great NAS though. And also, it's only a NAS. It's not an application server like a Synology NAS.
I only wish UNAS support ZFS.