First, I have none of this equipment, so I can't just test it and see ..Yet. I Know I could hack a Time Capsule into a RaidBox via SATA/eSATA connector, But that's not the route I'd like to go.
If you plug in a NAS to a A1470 TC does acknowledge it's existence ? And Can you store to it? I want to get a TC A1470. replace the small drive with a larger TB unit. Use that for my Time Machine Backups. Then add a 16TB NAS (wired) to the ethernet on the TC. Like a Drobo 5-Bay DAS Storage.
Mac, Mojave, External NAS, Time Capsule,