If I'm a beach hunt, or relic hunting environment (ghost towns, cellar holes, ruins, old-town urban demolition), then no, I don't pass penny signals.
But if I'm on turf hunting for old coins, then Yes: I pass all shallow pennies. Depending on the park (and normal depths of coins in certain parks) this depth cut-off for skipping can be 4" to 6".
I know that some md'rs *bristle* at that. They will say: a) "Sometimes an old coin might be shallow", or b) "a big fat man's gold ring could read up high into the zinc or penny range" or c) " Why skip pennies ? They add up after all"
However, if you hunt with those persons long enough, the proof starts to be evident: They end up with scads of clad, and very few oldies/silver.