Shoot, I'd be happy just being able to manually do it from 'frame and focus' using live view. Give me an HFR read out, a zoom option, and a 'in' and 'out' on the screen. That's exactly how qDSLRDashboard works and it's really painless.
I think most people who would use a camera lens are probably doing it in the field anyways. We're probably watching our gear and you could use the manual focus reminder option to do it every hour or so.