I just tested something old but interesting which applies for woody headphones. Since I have 2 pairs of W1000X, 1 with over 500 hours and 1 brand new, so I took out them to test the burn-in process of typical woody headphones. Conclusion was that there are at least 2 stages of burn-in time. First was 48th hour mark to get rid of the cold, harsh sounds of new headphones. Second was at 100th hour mark, this is where you starting to get all the details and sweetness of woody sounds and also the final stage of burn-in process.
Properly I can test my A2000Xs too since I have 2 pairs as well XD. 1 with over 250 hours and 1 brand new.
I own WA6 with Sophia Princess 274B rectifier and 6GL7/6EM7 drivers with less than 100 hours. I tested with my Audio Technica Trio W1000X-W3000ANV-W5000. I found WA6 is quite a good match for typical Audio Technica's woody sounding but not so much with "A" and "AD" lines. I also found WA6 incredibly matching HD650 and AKG701~702.