Thanks everyone, I know that you all have very good reasons for doing it the traditional way. It's simple and straightforward... I'll do it already!! However, I'm also wanting to take a fresh look at this and explore something different. Let's leave it at that. Besides, the more exposure mistakes I make, the more film I use and the more I'm feeding the market!
I really believe that having an intuitive grasp of how subject distance relates to bellows factor would result in near instantaneous exposure compensations, in your head. It's much easier to estimate distances on the scale of feet and inches rather than mm or cm.
Now, what was it that Robert Frost said?...