That’s an interesting approach for spent pucks. Generally, the pattern I’ve seen is radially, higher extraction on the sides than the middle. I have explored TDS across the filter screen and I’m working on an updated experiment, but it’s hard to measure.

One of my core competencies is image processing, and I’ve analyzed a few videos of shots (I have a video for almost every shot), but you can only see half of the outside of the shot.

That being said, I think tiger strips are indicative of uneven flow like you mentioned, but I haven’t gone to measure it. Most of my post puck analysis helped me improve the donuting.

Filter baskets themselves are part of the cause of channeling which is why a cloth filter does so well to improve extraction yield.