I replaced my SRAM Red FD with a Ultegra 6700 FD. The Ultegra FD has a more narrow spacing between the inner and outer cage plates, perhaps because Shimano shifters have trim shift position. I could not adjust the 6700 FD such that I could use the small chainring with the 13, 12, or 11 tooth. I "tuned" the Ultegra by bowing the outer plate a bit, now I can use the 13 and the 12 with the small chain ring. I put the handle end of a 12 inch Cresent wrench between the plates and then twisted a bit to add a bit of bow to the outer plate just where the chain is when on the 13 or 12. Now the front shifts as well as the back.

Seems to me like a lot of trouble to go to so that you can ride cross-chained.

You shouldn't use those combinations anyway, especially the small ring and the 11T. You'll wear out your narrow 10S chain even more rapidly.

+1. Great way to lighten your wallet a bit quicker. Plus it feels horrible, not what you want from a Red drivetrain.

I never use the 34 with the 11T or 12T. Before I tweaked the cage I could not use the 34 with the 14T or the 13T...