Couple of misconceptions here: the map is not short on space if you use that word purely in the volume sense. Large parts of C24 are gone, and both the sewers and CAB area use televators to take people there. So due to hammer map sizes being a cube, these three layers can be stacked vertically without impacting each other. So rather than there being more empty void, there is a bigger office.
If you use space in terms of resource cost: it is basically a box. If you make it smaller it will still be a box. Short of removing it entirely there are no significant savings to be had, even if you do remove it the savings are minimal and not really worth it.
So IMHO I do not see why having a large CA office isn't worth it. The only thing you can say is that you don't like it, as the size of the thing is purely down to taste.