I saw a 5-axis CNC machine on "Car S.O.S." TV show. It was used to clean up intake and exhaust ports on cylinder heads. Watch Car SOS | Disney+ S6E10
Since I don't have Disney+, here's a screencap from a mildly dubious source (albeit right at the top of Google results ): I've labelled the 5th axis because otherwise it just looks like a standard 4-axis trunnion table machine (which would also have done this job just fine). It's pretty cool, I haven't seen one like that in a VMC style before- tilting heads are pretty common in bridge/gantry machines though. The chatter sounds and looks horrible though, I wonder why they used that enormous gauge length when the ports were so easily accessible?! The whole point of porting is to smooth out the airflow and they just put a bunch of wavy lines in there for no good reason. Especially on cast iron, which should just make a "whsssssssss" sound when you cut it, it's wonderful to machine. Maybe they sat an intern down with some emery strips while they were off shooting the next segment.