You can get all kinds of opinions on this. We all have our preferences on all kinds of things.
I’m like CT, I believe people care a lot more about whether the roosts are narrow, wide, flat, or round than the chickens do. I’ve tried a lot of different things, they all work.
It sounds like they are perching (playing on them during the day) and not yet roosting (sleeping on them at night). Not that it matters as far as this question goes, they are so young.
The way I determine the height of the permanent roosts is to figure out the height of the floor, including bedding. Then I position the nests. Some people like the nests really low, some put them up higher. You want the lip high enough the chickens can’t scratch trash from the coop floor into the nests. Some people, say they have a bad back, may want the nests high enough they don’t have to bend over to get the eggs. Again, nest height is something people worry about a lot more than the chickens do.
Then I put the roosts noticeably higher than the nests. They tend to like to sleep on the highest thing available (flat, wide, narrow, round, or in the nests doesn’t matter to them) so you want them to decide on your roosts, not in the nests. They poop a lot at night and you don’t want poopy eggs.
I saw a broody hen take her chicks to the roosts at two weeks old. She told them to fly up and they did in two feet vertical increments. Even at two weeks they can fly really well, they could have easily gone a lot more than two feet. There is nothing wrong with having intermediate steps like you do, that can encourage them to get up there. Just because they can fly like that doesn’t mean they always want to bad enough to do it.
I want my main roosts high enough that the older chickens can’t peck the feet of chickens on the roosts. I integrate younger chickens a lot. If the roosts are high enough it gives the chicks a safe place to get away from the adults. Not everyone integrates new chickens.
I still want the roosts as low as they can reasonably go. Some people worry about the chickens hurting their legs when they jump down. If you have heavy chickens for the breed, like show quality chickens, that can be a concern. Mine are not that heavy for the breed though so I don’t worry about them jumping down, mine fly down from my 5’ roosts anyway. But the higher the roosts the more clear area they need to land when they fly down without bumping into something like walls, nests, feeders, or waterers.
I suggest you have your permanent roosts in when they do start to roost at night. That gets them in the habit of sleeping on the roosts and not in your nests.
Good luck!
