The reason given by Lockheed in the PSC was that Lockheed did their flight test program with and without Static Wicks and there was no difference in interference on any of the radio system ( which included the ADFS)
Your correct. However, the L-1011 CDL covered operation with missing "Static Wicks and as the CDL was customer specific there were differences in the number of "Static Wicks" that could be missing. To the best of my knowledge only TWA actually allowed operation with all "Static Wicks" missing.
PSC stands for Product Support Center all corrospondance coming into and going out of the L-1011 customer support was assigned a PSC number.