In terms of similar “interesting” things one I successfully did in the past that I wanted to share was to have a single Linux environment that you could either boot into or run in a VM.

VirtualBox supports fake disk images that are just pointers to a real block device, which could be an entire drive or partition.

I took advantage of that to have a dual-boot Linux & Windows 7 install (with the main bootloader still being Windows’ as I hate GRUB) and then created a VM pointing to the Linux partition.

The system was configured to be able to deal with both the real hardware and the VM emulated HW. As far as I know most stuff worked out of the box, the only change I had to make was have two network configuration entries - one for physical hardware and one for the VM.

This worked really well actually and performance was good.

https://github.com/DualCoder/vgpu_unlock

Looks like it can enable a virtual GPU so you don't need to actually use 2 GPUs, but I haven't tried it, it looks pretty cool if you only want to run only 1 to switch.