I ran into a related issue while I was looking at power meters. I wanted crank based power, and I had to choose between either something entirely 3rd party, which would have required 3rd party rings and departed entirely from the Shimano Ultegra aesthetic, or something like the Quarq DFour which would mate up with Ultegra 6800 rings, or the DFour91 that would have mated up with the new Dura Ace generation rings (or apparently also R8000 Ultegra rings, albeit imperfectly). In the end the Stages L/R was my choice, being built on a bog-standard Ultegra R8000 crankset. Of course that means I'm locked into Shimano R8000 generation chainrings, but that's what I chose, and now I'm dealing with one of the ramifications of that choice. I'd still probably choose it again, knowing what I know now, despite my misgivings on Shimano's choices and offerings.