Try driving on those aluminum pedals on a wet day. Have fun.
The reason why this car is harder to heel-toe on isn't the pedal placement. It's virtually identical to every other manual BMW I've ever driven. The problem is the pad compound and brakes are from the CSL/Competition package but on a lighter car, so you don't need much pedal pressure to haul the car down from speed. That's another reason why it's easier to heel-toe when pushing the car, because you'll be pressing down harder on the slow pedal thus making it easier to roll the foot over to heel-toe.
Unfortunately for me, I've had way too many ankle sprains to be able to move my foot freely like I used to in my teens. What I do for heel-toe now, is I place the ball of my foot underneath the big toe on the right hand side of the brake pedal, brake, then rock my leg from left to right to rotate the right edge of my foot toward the gas pedal. The only thing I find different with the MZ4, is that you need to hold the gas pedal for a split second longer than the mechanical throttled BMWs of the past (My E46 323Ci, my Z3 1.9L, and my E30 318is are all mechanical throttled BMWs. Although the E46 is a partial mechanical throttle). The electronic throttle seems to have a weird delay. Much easier to hee-toe on the street with sport mode on, but I've learned to adapt.