layer adhesion not an issue - but it's essential to have cooling on the area currently being printed.

You are extruding a cylindrical bead of plastic at between 200-220c (for pla) At this temperature the plastic is fairly fluid.
The slicer worked the printing out based on a perfectly cylindrical bead. The larger the bead the longer it will take to cool to a point where it stops being fluid and the more chance that it will slump and deform away from a perfect cylinder.
So the faster you can cool the plastic bead, the less it will slump and the rounder it will set. This will not only give you better prints with better layer adhesion but also allow you to print a larger bead hotter and thus faster. But you absolutely need fans or ducts blowing on the print area to set the extruded bead as fast as possible.

pretty sure you mount these on the end of the robot arm and run ducts to the nozzle.