I have the borneo xxl and found that putting a cardboard box in the base (some of the base) as a digging box helped give my hamster a nice deep area where his house went. I always give them bottomless houses on top of deep substrate so that they can make their own burrows).
I did also use lots of shelves and hammocks as my love!y syrian hamster, Arun, didnt chew fabric.
I agree that the big doors are great and that is is quite tricky to put together as the bars like to keep trying to fold! Once up it is lovely and sturdy.
Cant really see the cage but it was too cute not to post
Set up with hammocks etc
Bless you Arun. Much loved and missed x