LMan,
Certainly doesn't make any difference to me.
I try to teach my catchers to always appeal a "checked swing ball" call if there's the slightest doubt, regardless of the BU's position.
For some reason, this is not instinctive to them when I get them. I "harp" on it. I know I'm starting to get through to them when they either:
a. Appeal on a checked swing
strike call - I assure them that that's not really necessary
or
b. Appeal when there is no BU.
This pleases me, because it shows they are starting to develop the "instinct".
Once when this happened, the 1B coach banged the strike on his batter. He may have just been kidding, but I think he was really just pissed off at his batter for chasing a pitch at his eyes with a 3-0 count.
JM