Referring to your first post, I think you're on the right track. However, I think that the density you want over FB+F for Zone I exposure is not one stop as measured by the light meter, but a third of a stop (=.1 density units).
This is if you accept that .1 over FB+F is the right Zone I negative density, which it commonly is held to be.
One problem of doing this is that the gradient of the characteristic curve is pretty low at this part of the curve. So it's very hard to discriminate between adjacent settings if you have used, say, 1/3 stop increments in exposure. Or in other words, the speed you'll choose is very dependent on the shape of the foot of the curve.
I have seen it suggested that it is better to look for Zone III being 0.4 density over FB+F, on the grounds of this part of the curve being much more linear. Zone III will theoretically be more influenced by development, but it was suggested that it was not by much.