Better to have a bit more than less. Oil level doesn't effect pressure directly. As long as the suction screen is covered the motor doesn't "know" the level. That said a low level can effect temps and that can effect viscosity, which will can cause a minor decrease in pressure.
I run 6 quarts because the roll of toilet paper in my bypass filter sucks up one. That leaves 5 in the sump. Prior to that I ran for years with the 4.2 quarts my book says. Never a problem. Engine burns very little oil and doesn't leak a drop. I don't check it often because I've never seen a reason to do so.
Currently running Penn Plat 5-20 but I'll be trying something different soon. No brand loyalty here since GC disappeared. These days I buy whatever Grp 3 or better I can get on sale/rebate. Since modern oils are all good it doesn't matter and doing it makes for very cheap oil. Imo boutique oils are money down the drain.
Dub: Stop breaking your motor during hard turns
