we have just released a new firmware version (2.6.10) that introduces a new option - Print Speed Adjustments which allows you to control the speed of printing. It is avalable for the M Series Plus and M300 Dual.
As always - you can download the firmware at the Zortrax Support Center.
You will find all essential information regarding the new feature over here.
We encourage you to test the Speed Mode option and share your feedback.