A(0.55 micron)/A(V) does not always equal 1 for R(V) dependent models

[karllark]

For some models, A(0.55 um)/A(V) does not equal one (close but not exact). This the case for G23 at a minimum. But not for CCM89 for example. This is likely partly related to the assumed wavelength for the V band by the creators of the different R(V) dependent models. Or if the creators used photometry or spectroscopy for the optical (only F19 and G23 used spectroscopy so far). This can also lead to R(V) derived from the extinction curve not equaling the input R(V), depending on the wavelengths assumed for V and B in measuring the delivered R(V) [reported via email from a user].

This should be evaluated for all models and, at a minimum, reported/discussed in the docs.