L.U.P/PSI question

I'm considering two 12GA loads that are identical with exception of wad and LUP. One is at 9,400 and the the other 10,400. Here's my question... since they are both in the safe range, would I expect any actual field performance difference based purely on the lower vs higher LUP? I know that the wads may perform differently themselves, but I'm just interested in understanding how LUP affects performance in and of itself.

At that pressure level you probably won't notice any difference at normal temperatures. The load with the higher lead units of pressure reading (abbrev. 'LUP' may work better when it gets cold, but the only way to find out for sure is to shoot them both when it gets cold.