Exactly and maybe thats the point why this speed setting doesnt help much. With other printers I dont have this problem at speeds around 30-80 mm/s on wall speed. I only have to reduce the speed for small parts. Also slowing down the print while maintaining this high temperature for faster printing is also the opposite of helpfull. Nearly all my PLA Filaments tend to curl on the X1C. The molten plastic gets dragged around leading to bad overhangs.
I tend to use this hollow pyramides as calibration tools to dial in my final retract, flow and temperature settings. They print beautifully on a good dialed printer (without z-hopping) , but its a big fight on this machine.