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you can reach corner speed very quickly when you start microstepping-right?
Microstepping doesn't help in acceleration at all, as it doesn't increase torque. You just need more steps for the same speed.
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At >5000 pps, torque is about 25% of peak
But you need 1600 pps only, so you're far above these 25%. And yes, to increase torque at higher speeds, you need more voltage.
I have the impression you make too much a headache about the issue. There's plenty of experience, so you can safely assume a standard configuration works. And you can always increase voltage (within the stepper driver limits) later.