Interesting. I used to program CNCs (lasers and punching machines) for automotive parts. We couldn't rely on the path planner either. If the punching machine's turret ran too close to the clamps, it would crash and put it all out of alignment. There goes a day of production. The planner assumed all material was rigid, but when perforating thin material that wasn't the case. You'd end up with corners bouncing up into the turret that get caught and crumple the sheet metal like paper. The third issue happened when the auto path wanted to change tools multiple times.

It turns out that manually programming paths to account for those issues actually generate hundreds of saved production hours per year.