Couldnt you build a pickup that was two headed and had a trap door in it that closed one way or another under braking or acceleration? Getting probably too complex but just a thought? I do like the idea of a scavenge system you have but what about a possible simple mechanism at the front of the pan that uses the natural force and velocity of the oil under braking and routes it back to the pickup chamber. Seems a simple set of tubes would do that you'd just have to figure out the flow rates and stuff to have it barf it back around through the tubes.
That's not close to a true statement and if it is I don't think all of them are from oiling...most are from boneheaded mistakes or throttle input mechanism error.
But overall I get your point. If the cost is a wash then folks will migrate to dry sumps.