[C3L1CA]

First: if you can see debris on the top side of the cracks and could get it with a pick, how do you know the bottom side is clean? How are you going to get at that with a pick?

B: Hot oil and with the hot oil splashing around can cause some weird things to happen.

A filter on the pickup doesn't always stop everything or much of anything little. On an expensive engine build like this, an oil pan isn't all that much for peace of mind.