>  the multi-region awareness code [will] be [...] in the `BlackoilProperties*` classes, but not in the `Pvt*` classes

Can somebody, anybody, then *please* answer how we deal with functions that vary **independently** of the region index (or indices)?  That situation is especially prevalent in the case of saturation functions (relative permeability, capillary pressure) but hysteresis or end-point scaling effects must be taken into account even for pressure-dependent quantities.

Clearly linear transformations can be applied once a background value that depends only on the region is available, but that does not handle the case in which there is a non-linear relationship.