I have no helpful advise other than it looks great, but I had to laugh at your photo as bun is clearly plotting whether they can jump onto the heater...
A lot of us are jealous with you having your bunnies in your bedroom, they will have a happy life living with you.
I have a similar set up to you but we have it in our lounge. We have a regular a wooden hutch, not two levels thoufh and then we use a pen to extend Buns hutch space. The pen covers up wires and behind the sofa where I don't want Bun to go.
In the evening, bun is not only let into the pen but able to roam free around the house. At night, for his own protection I put him back in his hutch until morning. He seems to like this routine now and I've never seen him suffer for being in his hutch at night as long as I give him something to do.
Outside the hutch and in the pen, I have popped a rug down as we have laminate flooring. Bun loves a soft cushioning underneath. He still slips when he runs on the laminate but when he was young, having the additional carpeting definitely helped. His favourite spot is under the table on the circle fluffy rug. So I would definitely recommend some kind of rug even if it's small.