Couldn’t you just remove the middle 4 completely?
One of my customers wanted a two-screw vibrato for smooth and quiet operation, but he also wanted his Strat to look like an old one. I used a hardened steel replacement bridge plate designed for six screws, and the screws I used were stainless steel. I installed the two outside screws, and then cut the heads off four of the screws, leaving a little 1/8" of screw shaft under the heads. These I mounted in the four middle positions in the bridge plate with CA. Looked completely original and worked perfectly. It's still working fine after more than 15 years.
This was on an older ash body. Some modern bodies are fairly soft wood, so if you want to try this, you have to evaluate the wood to determine if it's hard enough to do this mod. If it's a softer wood that's getting an opaque finish, you can install hardwood plugs where the two screws go.