Okay, some progress on my various USB drive issues.
After updating to 2021.32.5, I'm not sure it rebooted the MCU, so yesterday I removed all USB drives and did a scroll wheel reboot. I then put my Sandisk 1TB NVMe (as above) in the glovebox and it recognized it (as before), I used the MCU to format it (and it did, as before), but now it's using it! So maybe something in 2021.32.5 fixed/enabled that functionality. Dashcam and Sentry are verified working with this device plugged into the glovebox port.
I haven't had a chance to verify my USB music drive works in the console port(s).