Seems to me that USB3 boot is no more broken then USB2 boot, namely there is a period of time where the keyboard (and mouse) don't work. I came across this recently when I updated my computer by moving the hard drives over, boot ended loading the network drivers due to having gone from realtek to intel with the "press enter to continue" message and enter not working so I had to power off, boot the AOS USB stick, go into the maintenance shell and rem the offending line out of the config.sys. Then boot worked and I could install the correct driver.
As Lars said, there's just a short period when the USB drivers (probably USB Keyboard) haven't initialized.
As Andreas said, you really should be asking Louis about this stuff and asking if you can get access to a beta build of the USB3 drivers, as it wouldn't hurt to have someone with Ryzon machines testing.
Are you really not allowed to go outside for a walk or such while maintaining social distancing? Or do you just live somewhere where it is hard to get outside due to shared lifts or such? The wife has been walking to the mailbox most days, about 5km round trip, and talks to the neighbours while standing on opposite sides of the road. Our road is pretty dead traffic wise.