The whole issue of using a 180mm rotor confused me. First off, all you need to do is use a “front” adapter on the rear caliper with the A2Z. The adapters all say either 140R/160F or 160R/180F. Use the adapter that says 140R with an A2Z and all is fixed. I learned the hard way when trying to use some XTR 965 ISO brakes. That setup would have worked fine if I used “front” calipers fore and aft. Who made the standard 20mm different for the front and back anyway?
With a Schwinn banger frame, I found that the 180mm rotor rubbed the lower pivot bolt and should not be used, so I consider a 160mm rotor the max on those frames (never tried a 170mm).
BTW, that Woodman looks great. One complaint with an A2Z is that the bolts are so close you may have issues. I went to the hardware store and bought “button head” bolts to fix the clearance issues. I failed to use blue lock tight, and had to frequently stop and re-tighten the bolts and align the caliper. The Woodman looks as if it would work with standard bike bolts.
Just my 2 cents.