(+) Among the variety of shapes and colors, I've picked out a capsule holder, which is not prepared on the table / cabinet, so does not take up space. The thing hanging on the wall and could, if fully equipped with capsules go through even as "abstract art".
(-) The capsules hang at a slight angle to the tracks. When the clearance "guide rail - backplane" would have been somewhat smaller, the capsules were sitting a little better and could be easily removed anyway.