It's quite a known thing for Porsches to have a lower throttle pedal in retrospect to the brake, which makes it tricky to heal & toe.
Personally I find it really easy, I've no idea why. Maybe I've got used to it. I heal and toe on the street with regular street driving too, even driving slowly. It's much better than letting your transmission slow the car when you select a lower gear. Brake parts are cheaper than transmission parts