OK you’re allowed to just not do that.

The rest of us who are willing to put some effort in will likely not notice your absence.

I think their point is, yes, of course you can use another engine, because, at its core, an engine spins a drive train. That’s all it does. However, to replace one engine with another, you may need to change every hose, mount, sensor, and customize the computer, because what it shipped with assumes you’re using… What it shipped with.