I've had the test results sitting in my drawer, with the intention of posting them here.
The good news is that all my samples tested negative for all 5 viruses. The bad news is that orchid fleck virus is very possible, and likely according to the virologist, but they have neither the antibodies nor primers to test for it. Symptom development matches what I see. Young leaves go a long time without visible signs of injury, but on older leaves symptoms first appear in the mid part of the leaf, with circles and stripes. I wish I could test for it, it would break my heart to toss the irreplaceable orchids without the certainty of knowing if it's OFV.
The black spots/streaks are the bacterial pathogen Acidovorax cattleyae, and that I can do something about by increasing air movement.