Increase Steppe motor speed

I used this site below to calculate the Maximum speed. Considering a full step i.e. 200 Steps/ revolution (360/1.8):

Maximum Speed: 0.592 revolutions/sec

Minimum Time/Step: 8.44 ms

Maximum Power: 15.9 Watts

considering microstepping like 1/4 I will have 800 Steps/revolution in this case I will get:

Maximum Speed: 0.148 revolutions/sec

Minimum Time/Step: 8.44 ms

Maximum Power: 15.9 Watts

If this is ok (I dont know if I will be missing any steps) what would be the best default values for MicrosBetweenSteps and MillisBetweenSteps to get the higher velocity? Can you help me understand how I can calculate these values?