Advice for my new bird box

On the 12th November we had a blue tit come and eat the spiders’ nests in our camera bird box. It has returned every evening to roost for the night. Without the spiders in there, the box is looking pretty empty and so I was going to place some nesting materials around the garden. The bird is gone all day (I guess far away) and so is it likely to see materials that I put out in my garden? I do not want to risk scaring it off (I can see from the camera when it’s away) but could I give it a helping hand by poking some fleece through the hole? The roof has started to leak slightly on very rainy days, again not wanting to scare, am I ok to try to patch this when it is away?

Any advice would be greatly received, this is my first bird box and you can probably tell I’m a bit excited/overwhelmed by it all (like being a new parent again)!!!