So my friends and I are starting up another campaign and we've decided to go in an an order of dice together. We're thinking we want a symbol for the ones, a different symbol/color for the fives and sixes, and then we could just leave 2-4 blank for each removal after a roll. Before we order, though, I thought I'd query some other Shadowrunners on where we'd ever actually need that 2-4. I'm pretty sure they're unneeded, I can't remember using them, but I'd like to be sure before I spend like $200.
Related, how many do you think would make for a good pool? Is 20 enough dice? I can imagine needing up to 30 in really extreme situations? What's the theoretical maximum number of dice you might have to roll?