My gaming friends & I here in Florida have been doing this a little differently, probably due to our having played SAE before. We roll the dice for a weapon or weapons to hit, then the defender makes shield saves vs any that hit. Any weapons that are not intercepted/blocked by this shield-roll get thru, then hit the target, "explode". They do the number of points of damage based on any weapon traits Dx2, Dx3, Cts, etc.
Statisticly, the damage is the same, but it saves a Lot Of Time doing it this way.
My largest DN has a CR of 710, and one battery that has {Acr,Dx2.Dx3} and another with {Acr,Dx3,Cts}. (It also has 58 hull & 58 Armor). The way we do weapons-fire & damage goes much faster; fewer die rolls.
I believe that statisticly, the results are the same.
Cheers 8-)