Wilson K4 Pickup Question

[Deconrad]

Hi: Is anyone here familiar with the Wilson K4 upright bass pickup (https://wilson-pickups.com/product/k4/)? This has 4 separate piezo pickups mounted in the bridge, very close to where the strings cross over. The pickup came on my Pawlik EUB, and I like its sound a lot, but the A and D strings seem to have slightly more output than the E and G, and I want to adjust that. But the instructions on their site—"By simply rotating a pickup slightly you can adjust the volume level of each string individually making the perfect balance between the output from your strings, a feature not covered by any other competitor."—don't seem to work. I've found no more detailed instruction on this on their site or elsewhere. If anyone here has used that pickup and has any tips on it, I'd love to know. Thanks!