Using the design principal “KISS” (Keep It Simple Stupid), I created a light diffuser. This one is for the Olight Baton 3 Pro flashlight.  I wanted to use it as a small table lamp or hanging light. 

 I made it with PETG because of the heat the flashlight can generate.  Still, I don't recommend using this with the brightest “turbo” output levels because I'm not sure how much heat the flashlight might generate on the diffuser.  Besides, the brighter settings make it too bright to use comfortably.  This flashlight will drop out of turbo mode after a couple minutes as a safety measure. The diffuser has vent holes in the top to reduce heat build up, which also  has the advantage of still being able to pick up the flashlight and point it at an object to highlight it.  The diffuser 

Note:  The best print result I've gotten was from printing open end down and providing support to the entire inside of the cylinder.