Does a light crimp with the FCD or any other die help overcome some of the inadequacies in "normal" guns? I think maybe. Used correctly, there's evidence that it might. I say try it and find out.
In a high-end competition gun, no.
Maybe, maybe not. This test says NOT.
Check out the rifles used in this test. I would call them "High end".
223 REMINGTON: REMINGTON 40X, LEUPOLD 6.5-20X IN JEWEL LIVE CENTER RINGS ON KELBLY BASES.
243 WINCHESTER: REMINGTON 700 PSS, LEUPOLD 6.5-20X IN LEUPOLD MOUNTS.
308 WINCHESTER: SAKO TRG-21, BAUSCH & LOMB ELITE 4000 6-24 IN SAKO MOUNTS.
All three of these "high end" rifles showed improvement using the LFCD.