RE: Troubling observations about brushless . . .
These days people just use cogging as a catch-all word to describe a certain symptom. You just need a better battery or less system resistance. Real cogging is something else.
I haven't driven a truck/buggy/car yet where I couldn't flip it on a corner if I did something I shouldn't do. Even stock RTR stuff. Have you tried adjusting the anti-squat setting?
As for the cogging, it can flip a truck, esp. light stuff. More what you have to do to get around the cogging. If you have to jam the throttle down to get it moving, once it starts to move it can flip. This is how my mini-T was at first.