Mike; that would be amazing if you got your hands on an EX-800 and were able to 3-D print those buttons. They have confined my EX to a pillowcase in the closet, and nobody puts baby in the corner.
No idea about the durability of 3-D printed buttons, but if you can print a functional 3-D firearm, I'd venture that a 3-D printed buttons would hold up under stress.
-Charlie