Imagine trying to put power down mid turn, and instead of the car actually turning in, apexing, tracking back out, it just pushes away from the intended apex, you immediately push out wide and almost hit something, making you lift off, and now that you've caused the car to dive forward, the already overloaded front wheels completely run out of grip and the rear of the car swaps places with the front of the car.
The lift off oversteer probably wouldn't happen in today's world with ESC and ABS but that's the gist. Car won't have any flow and basically be a point and shoot car...only at like 300 hp instead. Even once tuned the VAQ can be overwhelmed and try to lock which causes understeer too. Best bet honestly would be a wavetrac/quaife if you plan on running more power than stock at all. They're hard to beat on a FWD car.