Saddle feathers grow in at the tail, hackle feathers are the neck feathers.
I'm not convinced yet that you have a boy there. When my boys saddle feathers came in, they started further back by the tail and curved downward. And they all had curved tail feathers before the saddle feathers came in. I don't see any of that in this bird.
I think it may just be normal feathering in along the back. At this age, they are still filling in. It still looks like a pullet to me. I wouldn't be rehoming this bird until you're absolutely sure. (like if it crows)
I'm not convinced yet that you have a boy there. When my boys saddle feathers came in, they started further back by the tail and curved downward. And they all had curved tail feathers before the saddle feathers came in. I don't see any of that in this bird.
I think it may just be normal feathering in along the back. At this age, they are still filling in. It still looks like a pullet to me. I wouldn't be rehoming this bird until you're absolutely sure. (like if it crows)