Not a bad analogy, but flying and floating have some significantly different properties. The main factor that keeps a raft afloat is the relative density of (raft + passengers) versus water. It would be a better analogy if we were talking about flying hot air balloons.
I don't have any definite answers here because there are too many factors interacting, but an open cell canopy "breathing" is changing size (and shape). One way to think of it is that your wing loading is dynamically changing. Lift = [some coefficient] * density * velocity^2 * wing area. Shrink the wing and you lose lift. For a stalled canopy, the rate at which you fall is presumably relative to the amount of fabric area above you, which would also be decreasing if the canopy was doing an accordion impression. Flying or falling, it would seem to make sense that a wing that stays rigid makes you less likely to hit the ground hard. Of course, in turbulence, the density of the air is changing as well, so that messes with the equation. But I'd also think a rigid wing may maintain speed better, which would keep lift up.
Even if we aren't talking about hitting the ground, more lift means more tension on your lines, which helps you stay in control. I think most of us would want airlocks if we were flying in air likely to collapse a canopy. I think in other cases, you may not notice these effects, but if you do, I'd think it would be in favor of an airlocked wing relative to the same wing without airlocks.