The length of pedal travel is part of the equation between pedal force and clutch disc travel. The factory chooses a pedal travel that allows what they think is optimum required force on the pedal. Shorter pedal travel means higher required force if you change it the right way - it's a system based on leverage, both mechanical and hydraulic.
We set up race cars with short clutch pedal travel by changing the throwout fork geometry. This increases the required pedal pressure as well as the stresses on the fork, so we machine them from better material than stock. But the actual travel of the clutch disc (and, therefore, the pedal) is dictated by the clutch itself. Carbon button clutches and competition clutches like 10,000 RPM, Tilton and CenterForce specify their desired range as well.
I'm not familiar enough with the MZ3 clutches to know exactly how little travel is too little and whether it's safe to remove any - but the above facts suggest that it's probably not a real good idea unless you know FOR SURE that BMWs will tolerate less than factory clutch travel. You get a very rough guide by engaging reverse directly from neutral, because reverse is not synchronized. If there's ANY noise, the clutch isn't fully disengaging. Properly functioning synchromesh will quiet engagement of all forward gears for many miles even if your clutch isn't adequately disengaged. You risk serious damage this way and you won't know it until it's too late.
If somebody out there truly knows that there's excess travel in the BMW clutch disc, NEVER MIND (as Roseanne Roseannadanna would have said).