Examples of "In CMYK is 4+0, 4+4, 1+1 etc" make it clear that it is about the print order in the print shop and their prices.
- 4+0 is a full-color (four-color: C,M,Y,K) on the one side, and unprinted on the back.
- 4+4 is a double-sided color print
- 1+1 is a two sided black and white (one color - black) on both sides.
Print index (spot) colors is usually considered otherwise and is more expensive since it requires additional preparation: a mixture of dyes, the preparation of dies, etc. So with Pantone usually printed in big print runs of 2000 copies.
The term "saturation/vibrance" definitely should be and for antonovskoe print. The number of used colors directly affect the price and the demands on the car. If the design involves more than 4 colours, will have to look for a printing house with a machine that can support a larger number of colors.
To say "4+0" about printing in Pantone colors is possible. Just make sure that you understand correctly that the printing is spot colors.