I would try free ranging, or at least, fencing off a larger area within your yard that they can use, to give them more space. You have enough space technically speaking, however the issue with super small runs is they simply don't have enough space to add clutter: https://www.backyardchickens.com/threads/a-cluttered-run.1323792/ which helps keep chickens busy and provides hiding spaces if they get picked on.
I'd also caution you on the use of the flock block - they might enjoy the goodies in it, but I bet it's diluting down the protein in their overall diet, which can contribute to picking problems.
I'd also caution you on the use of the flock block - they might enjoy the goodies in it, but I bet it's diluting down the protein in their overall diet, which can contribute to picking problems.