And FuriousGreg breathes a huge sigh of relief as he brings the last of the hold-outs into the fold....sometimes you have to be patient with us as we work through our own processes.
At the risk of sounding pedantic, not entirely
Cumbersome (or Unwieldy) does not stack. It's effects are cumulative, but the quality values are not added together. The big eye-opener was that Cumbersome should not be considered a weapon-specific quality when it comes to figuring out the difficulty of a two-weapon attack. It should be applied afterwards, just like it is applied to all skill checks.
Well not the approach, just the end result, I guess.