I really like QubesOS, but you cannot run VMs inside a qube, or other things that require VMs like Docker Desktop for Linux, because the xen hypervisor does not support nested virtualization.
Not a Qubes user, just a curious reader; what is the issue with this? It sounds like you’re implying that what parent said isn’t practical. I’m curious why?
The issue with trying to hack Docker Desktop and similar tools to boot a qube instead of a VM and somehow hack QubesOS to not isolate those qubes from each other seems self-evident to me and I don't care to explain further.