Cafelat Robot - Testing impact of using paper filter to reduce channeling

I've noticed some channeling in Cafelat Robot extraction depending on pouring technique, so I decided to perform a test to see if channeling is reduced by using a paper filter under shower screen. I deliberately poured water in a fixed spot - off centered - and I checked how extraction looked like from filter bottom.

After that, I started using paper filter in all extractions and I've noticed significant improvements in the cup, specially in terms of repeatability.

I used Aeropress paper filter cut to size and pre wet it so it sticks to the screen shower.

About the water leak in the end of second extraction, I'm not sure if silicon gasket is worn. I think it is related to pressure being too high during extraction. I had to push really hard to extract that one. When grinding coarser, leakage didn't occur, but I need to do more tests on that.