The dye is very potent, wear gloves and be careful of spills. You don't need much to leave clear indication of which weeds have been sprayed and which ones haven't; so no more double spraying some and leaving others untreated.
Impact of the surfactant is less obvious, but assuming it works as advertised, it will improve the exposure of the weeds to the herbicide, leading to more effective weed control of even waxy, herbicide resistant weeds.