The hypervisor + OS + application model is stupid. The hypervisor and OS are duplicative. If you can rewrite the application (as is needed for a unikernel design) there is no reason to use a hypervisor in your stack at all. You should just be running a OS directly on the bare metal with no hypervisor at all.
The only reason to prefer a unikernel is because you wrongly believe that hypervisors are a security boundary. Everything else about them is strictly inferior to a standard application on OS model.