I think possibly indexing too hard on the span numbers here
Reiterate that in waves with power is when the silk goes well (this is different to manoeuvrability), as said below, Prog foils are ultimate grovelers, I would say that Silk feels like a high performance shortboard designed for good waves. I don’t know how to explain that in any other way.
I had another session in good conditions and I think the key insight is that it is high performance and so sensitive to trim, you need to be able to move your feet around, and you need to have high sensitivity to the feedback you are getting from the foil, but when it clicks into place, it is incredibly agile, fast and smooth (and efficient - though I am in warm water, I hope this translates to cold water!).
Regarding the pump/glide, I also did a shore run chip in to test, and now that things are dialled in, it was surprisingly easy to lock into weak bumps. I wasn’t really expecting to downwind this foil very much, but now very keen to try it in powered carvy conditions.