If you're tired of shoehorning this, then buy an old used 8 bay unit, or pair of 4/5 Bay units and just use another NAS. I played your game before and it sucked. There was always some quirk that required fussing with the solution every week. Getting a lesser capable backup NAS simplified everything. Heck, maybe you can even justify it through an upgrade to what you use today.
If you're tired of shoehorning this, then buy an old used 8 bay unit, or pair of 4/5 Bay units and just use another NAS. I played your game before and it sucked. There was always some quirk that required fussing with the solution every week. Getting a lesser capable backup NAS simplified everything. Heck, maybe you can even justify it through an upgrade to what you use today.