[cypher]

The deep substrate part of the cage looks good for him although I understand peeing in the burrows can be a bit of a problem as we discussed in the other thread.
The igloo isn't really good for anything tbh, it doesn't look big enough & has the other problems I mentioned in the other thread so I would definitely go for a nice big cardboard box if you can't get a big enough wooden house, the house really does need to be quite big & dark.
I would try to get a large bendy bridge if you can & use that to section off the deeper area, maybe leave a bit of a gap underneath even so he could burrow through if he wanted too.
The rest of the cage does look too open & empty which will hold back his confidence & make him feel a bit vulnerable when he's out, I would put more substrate in that part too, as much as you can manage without the wheel touching the lid, it's hard to tell for sure but I think the wheel could probably be higher up if you got or made a shelf for it allowing for more substrate, I would also put more in that space, something like a cork tube or tunnel would be good (you need to freeze those for about a week before use) or cardboard tubes (check they're big enough) or just bendy bridges to climb on & hide away under if he wants too, that just makes more places to explore & forage as well as making him feel safer.
Try him with some things like chew sticks, hazel or apple twigs are good, a whimzee dog chew & a spray of millet, if he enjoys those that will also encourage him to spend more time out & about giving you more opportunity to interact with him.
Hope that helps a bit, others might have more ideas to add.