Renato said "USB 3.x ports must be placed far away from the antennas", so I gave multiple examples of that not being true. And you've said "Lots of devices still have the option to downgrade to USB2 in the UI to get around interference issues" as if it's a common issue. But I've told you that the Asus TUF AX6000 is almost identical to the GL-MT6000 and the PCB designs are similar, yet it only seems to be the GL-MT6000 that's suffered from interference, despite it having the USB port on the side.
I have other routers with USB 3 ports on the back and none of them have suffered from USB 3 interference.