I agree and the space for lights and such is really big, unless you are making that a storage area I would cut that down to six inches, that is plenty of room to do your light maintenance and such
if you want the storage then I would use a bottom area and bring the dragons t eye level like said
also a thing that people often forget is that beardies spend a lot of time in trees when in the wild and they will feel more secure, one of my beardies spends 80% of the time in the branches across her cage and on a ledge up high
and my other beardie who is a rescue and has some pretty bad MBD is always trying to climb the branches and logs
they also will usually sleep up on the logs which is usally a bit nicer to look at then a big beardie flopped on the ground lol