This level of conversion isn't exactly trivial but it also isn't rocket surgery for the kind of person who pulls an engine out for rebuild on a classic car project.
If you saw the "quality" of electrical work otherwise very smart car enthusiasts do you might think otherwise.
... so you're buying into a locked, digital control system, akin to what John Deere puts out.
This ranks right up there with BMW wanting to charge a monthly fee for heated seats - building in physical abilities, with digital lockouts. You know, you can buy a LS engine, and do whatever horsepower changes you want to it. For those more akin to computers than cars, this is called a "LS swap" and is common with restomods.
This is disappointing to hear and tarnishes a brand like Chevy. Fortunately, we're in a free market; I'll vote with my dollars.