Let me second the use of the EGW firing pin stop. It's Brownings original design. It was changed to the radiused firing pin stop in the A1 because soldiers complained about the effort needed to rack the slide.
What the square bottom stop does is decrease the mechanical advantage for the slide cocking the hammer by pushing on it further down, making it harder to do. That causes a slight delay in unlocking the barrel that gets the bullet out before the slide has moved back as much as when a radiused stop is used. Muzzle jump is significantly reduced, putting the recoil more straight back into your hand, so the gun feels like it is recoiling less and it definitely gets back on target faster. It just takes more work to start the slide back in a clearing exercise. But the spring strength and original battering tolerance assumed that square bottom firing pin stop would be used. Ever since the A1 change, things have been a bit harder on the metal.
Light recoil springs are necessary for extremely light loads. I used to shoot cast 185 grain SWC's over 3.8 grains of Bullseye in my Goldcup as a gallery load and as a 25 yard timed and rapid load. If the spring was the Goldcup standard 14 lb spring, the slide would sometimes fail to make it into contact with the spring guide flange. The gun feels very soft and mushy then, and if you limp-wrist your grip even slightly, it fails to feed, so I went to a 12 lb spring and made sure I had a little of that contact. I widened and polished the feed ramp on that gun until it would feed empty cases, and tried springs all the way down to 9 lbs to play with 3.2 grain loads (poorer accuracy) and never had a feed problem other than the limp wrist issue when the load was too light for the spring.
Going the other way, I got a custom mold made for a 300 grain boattail to shoot in the 1911. I put in an EGW firing pin stop and a 20 lb spring, expecting this big boy would need all the resistance I had. Nope. First, I couldn't safely put enough powder in the case to exceed 700 fps. Recoil felt the same as hardball. So, I went back to the standard 16 lb government recoil spring.
BTW, even with both the 20 lb spring and the EGW firing pin stop, 200 grain SWC's over 4.8 grains of Universal still functioned the gun just fine. A standard 1911 normally still functions with 185 grain JSWC's over 4.2 grains of Bullseye (a standard commercial match load equivalent formula). The gun design is very forgiving over quite a range, and sticking with the standard springs and the old John Browning firing pin stop will let you digest a huge range of loads without compromising the life expectancy of the gun.