Just an option
(never been tried never been manufactured - personally)
While i was cleaning up my models i was just playing with the cooling duct i figure add some details to the existing models and added a few options to think about.
Looks like the stepper is getting some heat thru the cooling block - conduction and convection
Maybe just maybe a phenolic insulator may help
OPTIONS - maybe help the PLA folks
Dream@night / Holdit@sameday