I would like to the ability to time the amount of work I have spent on each image. Simply set a clock to the image. I could then charge out my time based on actual working time. This data could be held in the meta data.
I do this the old fashion way with a timer. I use the digital timer from when i had a darkroom. i put the time in the file info. I know this is not what you want but is a simple alternative untill they can add it.