Had some problems printing a tall spire object on the top 25mm. Looked like a lack of cooling issue to me so I thought this fan shroud with blow ring might be the cure. The spire on the left is with the default fan shroud, the right with kbowley's shroud ver2. Same exact gcode file. Sliced in CURA 3.4.1 with CURA's default Monoprice mini settings. Monoprice printer set at hotend 210C, bed at 60C, speed at 1.0. printed with PLA. Huge difference! Got a little wiggly on the right one during the last 4mm, but I think I could solve that by slowing the speed down to .5 or .7 as it neared the top.
Great modification and fit perfectly on my mini. Big thanks to kbowley!