Excellent questions!

We've never had anybody ask this about an AIO, it is usually a mini PC.

Because of the motherboard chipset and 6th gen processor, using multiple USB connections (some belong to the chipset, while it belongs directly to the CPU) never w6ork out favorably. Part of the issue is the nature of HDDs being redundantly s-l-o-w (the read/write speed of an HDD, depending on RPM, is approximately 60/20MB/s)

Most of our clients invest in a new or used RAID enclosure, once they choose the number of drives they plan on using

ORICO 5 Bay USB 3.0 to SATA External Hard Drive RAID Enclosure Support 80TB, 2.5/3.5 inch HDD SSD Enclosure Built-in 150W Power/Dual Chip for Enterprise Server Expansion (Support RAID)-3559RU3

ORICO 5 Bay Raid Hard Drive Enclosure Magnetic Aluminum USB 3.0 to SATA for 3.5 inch HDD Tool Free Storage Case Support 7 RAID Modes Up to 80TB(5X16TB) - NS500RU3

This simplifies sustainability, and even in RAID 0 the speeds are nowhere close to maxing out USB 3.0.

Some clients build out their own version

ORICO M.2 PCIe M Key to 6 x SATA 6Gbps Adapter Card for Desktop PC Support RAID-PM2TS6

Enclosure Thunderbolt 3 Compatible for 2230/2242/2260/2280 NVMe SSD, Aluminum M.2 Enclosure Adapter with Heatsink -[HP5-Rose Gold]

Kastar AC Adapter, Power Supply 12V 6A 72W, Tip Size 5.5 * 2.5mm

C Power Supply Plug to Molex 4-Pin PC Fan Power Adapter with Switch 11.8inch

IDE to SATA Power Splitter Cable,LP4 4Pin IDE to 5 x15 Pin SATA Power Conversion Line Extension Y-Cable for Hard Disk

It's not our team's favorite configuration, but apparently it gets the job done.