My theory is that the "pool" is purely for guiding the oil draining after shut down into the bearing race. So that when the bike's parked there's oil on the bearing at cold start up. And all manufacturers know that street bikes (or cars) are never warmed up prior to the dash to work.
I've never had a problem with any of my bikes by filling the pool and redrilling just the holes.
Fact is once the engine is running nothing will be draining into the pool anyway so it's just wasted space and a cause of unnecessary flow restriction.