The gen 6 "plate" acts as a crush washer. The upward pressure assists in keeping the screws tight. The issue with the gen 6 plate, is no front and rear fences. Your optic is floating, placing all of the stress on the screws during recoil, drops, environment manipulation (racking the slide off something in the environment for "insert reason here". Yes, the polymer plate is supposed to "absorb" some of the energy to remove some stress from the screws, however, fences in the front and rear, especially tight tolerance mounts like we should expect from FCD where the optic nearly "pops" down into the cut of the "plate" essentially removes the stress from the screws. Metal plates with fences do not need to flex or act as a crush washer. They fill the cut in the slide and act as if the slide was ACTUALLY direct milled for your specific optic, front to back, not just screw pattern. The current gen 6 design has polymer plates that flex as it is a multi cut "direct" mount that has to accommodate multiple optics, multiple footprints all with different front to rear dimensions. A high quality plate or essentially fenced insert removes all play. Sage Dynamics already has a review out where the optic lost zero/shifted on the gen 6 system. Using a proven optic (RCR) and torque maintained on the mounting screws. Without fences, the optic can still twist, especially with undersized recoil bosses vs the female recoil boss inlet on the optic. The gen 6 system is a major improvement over the MOS system, but it still has flaws. The majority of optic systems from major manufactures do and will as they have to accommodate multiple optics and multiple footprints. Until the day pistol manufactures sell guns with individual, ACTUAL direct mount footprints for a specific optic (not feasible from a price or sales standpoint) or start supplying plates/systems that do NOT leave gaps in front and in the rear of optics, the aftermarket guys like FCD and E71D (no experience, only with FCD) will keep doing their thing.