I have tried to mass deploy Parallels Desktop as a step in the Task Sequence. But the Install Application step fails.
NOTE: For macOS BigSur using MDM is a must and spctl utility is deprecated there.
Parallels Desktop system (kernel) extensions were automatically blocked by the new macOS High Sierra security feature. See Apple's KB Prepare for changes to kernel extensions in macOS High Sierra for more details.
Execute Script step should be created in the Task Sequence with the command to approve Parallels Team ID:
The step must be executed before Apply OS X Image step: