A rocket engine is a long argument with physics, settled one tolerance at a time.
In a powder bed fusion printer, a laser draws a slice of a part into a bed of fine metal powder, the bed drops a fraction of a millimetre, a fresh layer is spread, and the laser draws again. Thousands of times. What comes out is close. Close is not flight hardware. The CNC shop takes it the rest of the way.
Two disciplines, one part, and a hand-off in the middle where mistakes like to hide. I learned in aviation that the most dangerous moment in any system is the handover. The machine shop is no different.
So the brief was not “teach people about 3D printing.” It was: give every operator on either side of that hand-off the same picture of the part, and the same standard for calling it done.