EXCELLENT point you have shared! I have had this stepper over a year from Onefinity because of Z dropping after I upgraded to spindle. Others on forum had reported similar issues, but after replacement and upgrade to Elite have had no Z drops until recently upon power startup. A very small drop and alarm, causing me to restart and home machine, never thought much about it until your post. I wonder how many others have had similar issues. Could the stepper motors not be powerful enough to handle the weight of the spindle and carriage? Did you contact Onefinity tech support?