Let’s talk about the conclusion first:

if you cut thickness mostly thicker than 6mm , autofocus help it faster piercing. if you  always change cut material from brass to stainless steel and carbon steels, the auto focus automatically read them， if you always cut thin metal thinner than 6mm, and not always change cut material, the autofocus no use.

Whats the advantages of autofocus laser cut head?

With the automatic focus function, the machine can automatically and quickly adjust the focus to the most appropriate position when processing workpieces of different materials and thicknesses. This can significantly improve the processing efficiency of the laser cutting machine, and the time for perforating thick plates will also be greatly reduced.