That orphan rate increase will go to whoever is producing the 20MB blocks, NOT you.

This depends on how miners are connected.

E.g. suppose there are three miners, A and B have fast connectivity between then, and C has a slow network.

Suppose that A miners a block and B receives it in 1 second. C receives it in 6 seconds.

This means that blocks mined by C during these ~5 seconds will be orphaned because B gets A's block first.