Thanks Adam, good to hear it is on your list.

Another feature I thought of is an image display mode to help utilise the zone system for choosing exposure. The grey scale tonal range would be discretised into integer EV stops (zones), and stops above and below a defined dynamic range coloured red/green as a warning flag that these tones would clip. You could then apply a +/- exposure shift to get the range of zones to map where you want them.