These are all good questions, but yes I would aim to always keep the pyramid damp. What I do is I spend a lot of time just staring at it, and past images of roots and what might happen and different images of how deep if at all should the pyramid be. These images keep replaying and gradually over time something emerges. Right now I'd like to know what is going on under the water line. I'm also not sure how close the water line is to the bottom of the pyramid. I didn't really think about it too much at the beginning.
Like the only reason I tried feeding from the bottom was just because I found the funnel, and what I was doing previously was pouring the nutes in from the top all around the stones and also at the base of the pyramid, and then I would spray a bit of water on the top to rinse off the nutes. So nutes drying on the surface is something I try to avoid, while acknowledging that it's not a big deal so it is relegated to a low priority.
I'll continue like this for as long as I can to gather as much information from this current grow. I have all these abstract images in my mind that all revolve around roots somehow being in an air gap, and also I have other auto images that make an appearance. Maybe all this will lead to something completely different, like re appropriating my old Shallow Water Culture (SWC), to incorporate an old eazyplug with a few stones. I suspect this is where this is all heading.
But at the same time I also work towards simplicity, but I already have that, just using the plug on a rack, is as simple as it gets and it works well, the only problem is the constant attention they require without any watering automation. So I guess I'm really working towards a type of automation that is as minimal and leak proof as I can make it, meaning as few points of failure as possible.
At one point in the past the pyramid was going to be a way of making my SWC work better, but now my thinking is how can I rope my old SWC gear to serve the pyramid. As I say that, I'm thinking maybe I can use two pyramids in a single SWC and have two of those units in the tent, So four plants growing, all sharing a single 30 litre res in the middle. That just came to mind now...hmmmm ...
I like where this is going...
EDIT: New plan is to water from the top with the panels in place for the next grow when I will use a full size plant. The bottom filling with the funnel will just be for this grow and maybe the next but only to take measurements when I need to know what's happening external to the plug.