Pluton,
The overhang of the plastic prism cap which houses the pop up flash is need by the flash so it can peek over various lenses and lens hoods. When flipped up the length becomes height. I use my pop up from time o time for very light fill but I also accidentally pop it up from time to time when I don't want it. It also catches on my small camera case. My vote is take pop up off. I'd prefer all space on top given to a better prism and viewfinder.
Dave