Just another information point.
A few years back, I asked VAN's about drilling holes in the center section spar web on an RV8 build, inside the fuselage. They responded saying I could basically drill as many 5/8" holes as I needed but make sure to stagger them, not putting them in a straight line either horiz or vert.
I have seen a lot of holes drilled in the gear towers on different RV8s, but that doesn't necessarily make it right, or safe; however, I haven't heard of anyone collapsing a gear tower on the RV8, either.
A&P, Tech Counselor & Flight Advisor