AIS lenses and trap focus

I can't figure out why there's no way of illuminating the selected focus point, or configuring the camera to shoot when the in-focus indicator is lit..

Am I wrong in thinking all the hardware is there in a D700, to make the hundreds of thousands of manual focus Nikkors out there able to take advantage of the wonderful af in the camera? The green dot lights up, and is super-accurate - couldn't it just be slipped into a firmware update to the release priority settings? I spent 20 minutes trying to find a Nikon contact email address and gave up...

Anyone have any idea why it's not a feature.. is it even possible? I trawled a couple of threads on the subject.. lots of information on how the technique works with certain Afs lenses, and workarounds for af-d but surely it's a matter of connecting two existing features, the rangefinder green dot and the shutter release.. Am I making any sense here, would anyone else find this useful? For me, being able to place a focus point on an eye and pull focus with a 105/2.5ai, and have the camera only fire when the eye is sharp would be brilliant. I hate having to chimp and zoom to check focus only to find it's soft on a monitor.. it would be a real help!
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