Assuming you mean 275/30/20 here?
I run 275/35ZR19 square on 19x9.5 wheels… the lateral traction is awesome. It severely annoys me to be on sensibly sized winter tires until April. While the wheels are off, I am contemplating shaving 3mm from the back of the wheels (+35 offset currently) to get it dead flush, if I can find a CNC shop that will do a good job for < $300.
Anyways, 275/30/20 would dent a little easily for my tastes (and local roads) but at least it wouldn’t let go in high-G turns. Having put fat summer tires on the 3, it’s tough to imagine ever going back. Drove from Michigan to Mississippi and back shortly after installing them, never had any issues with range anxiety, vehicle was quieter than stock running 275s at 37psi. I prefer to run square setups, but I’m guessing staggered is more efficient (albeit less performant for braking).