They say the Coco doesn't settle down. But I fill my Coco up to the top and drop the pot on the ground a couple times and fill it up some more and drop it some more. Then after all that it still settles down a couple inches in the pot and I throw some clay Pebbles over the top of that.
Most of the times my seedlings stretch up a bit, and it's kind of nice to be able to put a couple inches and Pebbles to help hold them up. But every once in a while I'll run into a plant that just insists on and staying very short and I get the branches sometimes growing almost out of the Coco.
Where I'm growing