I was tempted to get the TC14 Z mainly for my Nikkor 400mm f/4.5 Z and by a stroke of luck got it. The TC is surprisingly heavy and very robustly built. It has a tab on the inner rim of the bayonet, like the 'E' converters for F-mount, to prevent 'illegal' lenses to be attached. Legal in this context means a lens with a matching notch on their mounts. Being a nerd, I quickly replaced the original mount with a normal female Z mount so there isn't any tab. Thus many lenses will mount, in particular if a narrow extension ring is added to prevent the protruding front of the TC to crash into the rear glass of the hosting lens. However, if the host is a lens that the camera recognises, we are thanked by an error message of 'cannot shoot, unsupported lens'!! Shame on you, Nikon. The solution is of course to prevent the signals from the hosting lens to get back to the camera.
I must say the TC functions flawlessly with the new 400/4.5Z. The combination does AF a little slower, as expected. otherwise stabilisation functions very well. Thus even yours truly can shoot this combination hand-held.
Blur circles are nice, too.
