Nested Virtualization Risk and setup alternatives

I was attempting to setup Sosumi inside of Qubes as a means to getting Mac OS functionality.

The link below gives this as a possibility for linux systems through virtualization

My Rational is to setup Sosumi as a Linux Snap Package inside of QEMU which would be setup inside of Qubes OS through nested virtualization

What are the Security Risks and Implications of Nested Virtualization? Are there any tutorials for setting up QEMU KVM inside of Qubes?

Are there any alternatives to getting Mac OS functionality inside of Qubes?