I would not be dismissive of seeing dwv bees. It is the one classic symptom of varroa infestation.
You may see dwv bees at increased rates due to cyclical brood situations, and a host of immune weakening causes. But certainly seeing dwv bees crawling in front of the hives should be reason for concern and action.
You mention you are organic in practice. I say this in general terms. please do not think that beekeeping today is doing nothing until a problem exists, then taking action. Going chemical free or treatment free (Lets hold off on the rationalization of these terms and deal with the broader understanding) means using everything to your advantage. It does not mean doing nothing. Your equipment options (SBB, comb, etc.), your management (Requeening, brood breaks, splitting, etc.) and your bees genetics, all play into overall hive health.
I say this, because some will decide to go "treatment free" or just decide to one day, not continue their normal treatments. I have many beekeepers just say "I'm not treating my bees anymore! I want to go chem free". I say that is great. Then I ask them what is their IPM strategy and what will they be doing to offset the need for treatments. And they are lost. So they had crappy mass produced queens and bees, and think they will handle the mites on their own after being treated in the past. (Not that it means much as most I know who treat with everything in the book still loses massive amounts of bees) But I hope you get my point.
Most I know with success deal with from a multiple angle approach.
And the first thing most people suggest is "Throw some chems or acid in the hive". Why? Will that change the bees ability to deal with the mites three months from now? I suppose the knocking down of mites is good. But the bees also just told you (depending on what you find) that they can not handle the mites with the genetics and management IPM you previously used. So something must change. I would step back and think about what you could of done differently. And I also would change the queen. Some bees handle mites well, and some do not. Do not simply treat the hive and keep the same genetics in the hive. You will be repeating the situation over and over if you you do nothing.