I can't remember if I went 1kw or 1.25kw servo on mine.
I was always going to program the servo drive to run above the rated speed, but that's still on the roundtuit list.

My concern with going too fast with the stock setup, is the drawbar.
It's a fairly basic retention design, and I'm not sure how it would hold up to toolholders being spun at 10'000+rpm.