I've tried to passthrough Behringer audio interface, as well as HX Stomp (to, of course, avoid dual-boot) and it stuttered like crazy. Maybe there is a way to make it more "realtime" but it's not the default, at least in VirtualBox.

Yeah passing through usb devices to a VM for audio seems to be a dark art like working with a bunch of analog equipment. Everything has to be tuned. I do understand why a bare metal windows and/or mac computer is always in a studio, one can skip the head ache. Even if main DAW is Linux.