Parallels 12 - Hypervisor: Parallels or Apple?
This post in Parallels Forum clearly states to use Parallels Hypervisor:

Hi, Apple hypervisor comes short of the following matters comparing to the Parallels hypervisor:

Performance: slower on VM startup and shutdown

Stability: may crash more frequently

Functionality loss: no PMU, nested virtualization, thermal monitoring, energy profiling


Parallels Hypervisor is the best one.

By PaulChris@Parallels, a Parallels Support person.