This is quite banal to achieve. Just put Linux on its own disk and create a Hyper-V VM with the physical disk attached. If the disk has its own ESP, is it that

This is quite banal to achieve. Just put Linux on its own disk and create a Hyper-V VM with the physical disk attached. If the disk has its own ESP, is it that simple, just remember to use UUID everywhere and Linux will happily boot wherever you try booting it from. I've got an external SSD with ZFS + Archlinux that you can easily run via USB live or that it can be run as a VM via KVM/Hyper-V, and it runs flawlessly everywhere, with KDE Plasma, VS Code, Firefox, ... Performance is very good, thanks to Linux being way less I/O intensive than Windows, and USB 3.1 is actually faster than a SATA disk, so it doesn't suffer that much from booting from USB. I even had a Windows VM on that disk and it worked fine. Linux is way more flexible than Windows in this regard, you can install every single driver (i.e. both NVIDIA and Mesa at the same time) available and it will just load only the right one at the right time.