i would allow them to grow taller, and in more of a dome shape.
to be in proportion to the shape of the hardscape (so they need to be taller than the blyxa).
I agree, I think I do want it eventually to move with the contour of the rocks. I still need to get the iron supplement (shoot, I was just at a great place in Charlotte on Saturday!). Ugh.
Be lazy, be crazy, right?