I have every setting turned all the way up speed/accel/jerk is only limited by the power limits on the steppers. In the firmware speed is set at 300mms same with on prusa slicer. I just added zeros to the accel and jerk both in firmware and in the slicer. It's an ender 3 with an skr V2 Rev b board and a generic 2 into 1 hotend.

This was a very long couple of prints over 30 hours combined. It's for an Orion telescope that's why the Orion drawing.