Doing a quick look at the chart, it seems the Elemental Projector prefix is a better choice than Snowdrift, as even at 600% on Driver, the EP is still better (even for splash).
Have either of you (@DocStrangelove or @Prismatic) done any calculations as to where the damage from Victory Rush would enter the damage formula? Is it under gun damage or a special multiplier? Is it worth it if you can get it with the EP prefix? Is it possible to get the Pearl with the EP prefix?
To confirm i’ve understood not only the damage calculation formulas and the idea behind multipliers vs additives, but also your chart, getting guns like Storm and Firestorm (splash elemental weapons) with the +125% splash damage bonus is better than getting them with either phasecast or phaseslam bonuses?