Just ran across this, so figured I'd answer since I'm running Dominion A4s, currently with SRAM 200mm rotors due to availability at the time I built up my bike.
Dominion Calipers do not clear SRAM, Shimano, or some generic adapters I had kicking around - the caliper body interferes with the center bridges on the adapters. I haven't tried Magura adapters... those may clear as the Magura Caliper is pretty big and the adapters have a rounded cutout/clearance. I ended up grinding/filing my adapters down to make them work. So if you're running 203mm, I'd say just make your life easy and buy the Hayes adapters.
Jan. 18, 2022, 5:26 p.m. - Marc Fenigstein
Just ran across this, so figured I'd answer since I'm running Dominion A4s, currently with SRAM 200mm rotors due to availability at the time I built up my bike. Dominion Calipers do not clear SRAM, Shimano, or some generic adapters I had kicking around - the caliper body interferes with the center bridges on the adapters. I haven't tried Magura adapters... those may clear as the Magura Caliper is pretty big and the adapters have a rounded cutout/clearance. I ended up grinding/filing my adapters down to make them work. So if you're running 203mm, I'd say just make your life easy and buy the Hayes adapters.