some more moist sand. Medium viscosity, medium friction. Those are of course relative values but compared to flocking, compressed sand the description is okay.
143 frames @ 38h @ 2.717.112 parts per frame @ 10-80 steps @ 3 sandy-steps. ~16min per frame.
Speed of the new solver has already improved a bit and lower max substeps should do. Perhaps I will simulate the same setup once more and compare.