School me on vent plugs: I bought a Mercury Trophy prop for my Suzuki DF140. I understand the purpose of the plugs and utilizing vented plugs to enhance hole shot, but I have some questions. Currently all holes in the prop are plugged. If my hole shot is sluggish, can I simply remove one plug at a time to see if this helps, or do I need to utilize the vented plugs and have all of them equal? Can I drill out the solid plugs to create a vented plug? I'm trying to avoid buying three different sets as they aren't cheap.