Best Plate Coverage?

[SAump]

Passed ball or wild pitch to right-handed batter. Runner at 3B attempts to score run while pitcher covers the plate. Where should PU position himself for best possible coverage?

I have always told the batter to get out of my way and lined myself up with the extended first base line behind the plate so that I could get a great view of the touch/tag. But that view may also block my view of a ball that is dropped after the tag by the pitcher.

A partner suggested that I move around to the the first base side of the line or switch to the extended third base line but I feel the pitcher may block my view of the original touch/tag from these positions. Am I wrong?