Don't know what to say Boyan.

I have been using the same one on my test CNC builds (all of them) using a variety of steppers and aside from EMI shielding (which is a problem with almost every controller and USB, so I switched to ethernet right fast) I have had 0 issues.

I did use their stepper drivers though, those were just an amazing help as you can actually connect them over USB too and set them up in so many ways and test your steppers.

But even with hybrid servos it works.

Oh one other thing, I use Mach 4. Maybe that also plays a role.