I am wondering if you guys are seeing something similar.

I pulled the lever down with a light force, after a while the bottom of the basket is covered with beads of coffee. At this point, if I just ramp pressure I feel a certain resistance. On the other hand, if I let go of the lever or even raise it slightly (not enough to inject more water) and then re-apply pressure, I feel a much stronger resistance. It's as though the puck swells and close off channels if I gave it a respite from pressure. Is this normal? Btw, I WDT.

Thanks.

Yes, that's the same sensation whenever I do that sort of maneuver on my Pavoni or Cremina.

I have no way of proving this but my guess is that the pressure relief caused by lifting the piston and then subsequent recompaction causes fines to migrate to the bottom and therefore more resistance.

The change is so marked I doubt that's what's causing it. I would guess that with more introduction of water you're feeling water pushing against a coffee cake that's soaked across its upper surface and beyond instead of being aerated.

I am leaning away from fines migration too. If I don't do the lift, I sometimes get bald spots in the basket. I can see out gassing in those spots. If I do the lift, the whole bottom of the basket out gases. The second pull engages immediately, with zero sponges-ness. Seems to help reduce bald spots too. I am quite sure the lift is not high enough to admit more water because I can't hear any hissing.