I tried DoM for science in raid last night, and I have some suggestions for improving it. Hitting it every time it was up, the total DPS accounted for 0.5% of total outgoing (less than 1%). I'd suggest increasing each hit in the chain by 20x to make this about 10% of our total outgoing. Note: I am not optimized for auto attack, so for those swashies/brigs that are, this would be a bit less.
Another problem with this AA currently (as hinted in the OP) is the duration is too short. When this AA was introduced many years ago, recovery speed was still a stat for all classes, so it was much easier to hit all 8 triggers. I'd suggest changing the duration to 15 seconds.
Considering this is a shared AA endline with Brigands, we could improve and provide fun toys to both classes by modernizing this AA.