New Nikon 600mm F/4 FL ED VR is too front-heavy with D810 attached

Update 04.03.2017: Perfectly balancing a Nikon 600mm FL with a D810 / D500 works now. I not only replaced the stock foot, but also use the gimbal Heavy Duty MK IV by jobu design. Update 23.04.2016: Balancing the 600mm FL horizontally works fine now. I finally went with a foot replacement by jobu design. Update …