This video below without Fwed's ramblings has been posted by the owner of Ingenext. They do these kinds of Tesla mods, such as the boost module, as a business for Model 3 and Model Y. It was just a matter of time before they would start tinkering with a Plaid S.
If there is a warranty issue that comes up and Tesla can prove that your modification directly caused the failure in question the can refuse to fix said issue under warranty. The onus falls on the manufacturer to prove it under that act. In legal speak, it doesn't void the warranty, it potentially makes the warranty voidable which is a significant difference.