Virtualisation-based security features have a real cost, and the internet's answer is usually to switch them off. That advice is given without reference to what the machine is for or who owns the risk.
The published security isolation writeup covers enumerating what is actually enabled on your machine and what each feature is protecting against, which is the prerequisite for making that decision rather than guessing at it. Security isolation writeup.
Disabling a security feature to gain performance is a risk decision, not a tuning decision. If the machine is not yours to make that decision for, it is not a decision you get to make.