It's always a matter of increasing attacker cost. I am not sure that attacking QEMU, then finding a privilege escalation on the host that can break out of SELinux is much easier than just staying in the VM, hopping through the internal network until you find a host that lets you do what you want.
Chances are what you want is "simply" access to a shared folder rather than root.
Chances are what you want is "simply" access to a shared folder rather than root.