It's nothing special. I use Kubuntu on a MBP, and I've talked about how I've setup Plasma Desktop before on HN[1][2].
I run Catalina in a VM because it's the oldest macOS version that supports the APIs I'm developing against. I used to use KVM for virtualizing macOS, but VirtualBox[3] is more portable despite being much slower, so I use that now.
If you can use KVM with Virtio and VFIO passthrough, it's really fast. Linux just got Virtio-fs[4], too. I've had to pass boot options to the kernel to get the IOMMU to play nicely on the Mac, though, and I just don't have patience for that these days.
[1] https://news.ycombinator.com/item?id=23607374
[2] https://news.ycombinator.com/item?id=25172499