The silkies look to be keeping their distance, so that may be why they appear untouched. I know in my coop the top roost is coveted and the most senior in the pecking order get it. And there can be some battles for who gets to stay sometimes. My bottom roost is the least used (I have 3 levels). I also found that having more than one way up and down can help, less traffic jams if someone is being a jerk and guarding one. Having a divider on the roosts can also be helpful, gives them a wall to hide behind from others, doesn't have to be fancy or very high, just something they can't eat.
While to us humans it can look like plenty of room, they are telling you otherwise. I would also add some roosts or perches in the run, so they have levels to get up and away on. I have the crosswise across corners and use shelf L brackets and a piece of 2x4 to make short ones that stick out from the walls and posts. A small wooden or plastic chair could work, and also could work laying on it's side as a small wall they can 'hide' behind. Just make sure things are positioned so no one can be cornered. I use concrete blocks stacked for similar use, and can move them occasionally for variety, and they can get the bugs that moved in while they sat there. You can hang a head of cabbage, makes it harder to peck, keeps them busy. Try to think out of the box, nothing has to be fancy or expensive, just get the job done.
You might try physically moving them out of the coop a few times, they can be very stubborn and creatures of habit. Sometimes you have to MAKE them before they can figure it out. I moved a fence once and they would not cross the line in the grass where it used to be. I had to physically pick them up, one at a time, and put them over the line. Once enough were over there, the rest finally figured it out. You can also put dishes of food out there, to entice them.