To correct the issue, shut down the Windows 10 guest. From Virtual Machine Manager (aka virt-manager), open the properties of the Windows 10 guest. Click the tab "Controller USB 0", change the Model from the default of "USB 2" to "USB 3", and click button "Apply". Start the Windows 10 guest, perform the USB Redirect, read a disc, and verify that the USB resets and disconnects have ceased.
Additionally, after changing "Controller USB 0" to Model "USB 3", read performance increased from 4 MB/s to 13 MB/s.
The host's USB controller is USB 2.0. The USB to SATA bridge is USB 2.0. From what I've read, USB Redirect is limited to USB 2.0. I find it baffling that this minor configuration change has corrected the issue, but after reading discs for weeks without issue, it certainly is fixed.
I spent several weeks troubleshooting this, and I hope it helps others.
---------- Current Working Configuration ----------
Linux Mint 19.1 x64 Cinnamon (Tessa) running QEMU/KVM and Virtual Machine Manager
Supermicro X9SCM system board (C204 USB Enhanced Host Controller (EHCI))
StarTech USB2SATAIDE USB 2.0 to IDE or SATA Adapter Cable (JMicron JM20337 - USB 152d:2338)
Asus BW-16D1HT, LG WH16NS40, Pioneer BDR-209D, and Pioneer BDR-209M
Windows 10 x64 version 1909 (no additional Windows updates)
Architecture options: x86_64
OS type: Windows
Version: Microsoft Windows 10
Memory (RAM) MiB: 8192
Network selection: Bridge br0: Host device enoX
NIC: Device model: virtio
Enable boot menu: <checked>
Hard drives: Advanced options: Disk bus: VirtIO
Optical drives: Advanced options: Disk bus: SATA
Display Spice: Address: Localhost only
Channel spice: spicevmc; virtio; com.redhat.spice.0
Controller USB 0: USB 3
USB Redirector 1: Type: SpiceVMC
USB Redirector 2: Type: SpiceVMC
drivers installed from "virtio-win-0.1.173-5.iso" and QEMU Guest Agent "qemu-ga-x86_64.msi" installed
host/guest copy/paste from "spice-guest-tools-0.141.exe"
AnyDVD HD v22.214.171.124
IsoBuster Pro v4.5