Thus far, I have only checked the fit across several different frames and derailleur combinations and all the hanger/derailleur pairs work on the test stand. That's enough for me to pack a spare hanger in each of my backpacks so that road and gravel rides are both covered.
I bought a couple of these and keep them on my rowdier bikes just inc ase I take a fall and need to fix a bent hanger. I ride in some super remote places and have a bent hangar could cause a lot of problems in those instances. So along with a little bail wire, a couple of zip ties, spare tubes, mirco roll of duct tape, etc I know carry this too.
