This email predates the other one I posted and makes more sense with respect to what change was made to support the correct selection of bins:

My suggestion is:

Add a flag '.option wnflag=0/1'.
0 denotes that w is chosen,
1 denotes that w/nf is chosen for model selection.

In ngspice mode (and Spectre mode?) the option defaults to 0.

In HSPICE mode the option defaults to 1 (according to HSPICE manual).

The .option line will override the default settings.

The proposed changes will only influence the selection of a model
during the binning process. There will be no change to the model itself.

This fix will serve Tim's needs.

For HSPICE compatibility we might also add wnflag as a device instance
flag for BSIM4. The instance flag would overrule the .option flag or the
default setting (only for the specific instance). But we also might decide
to skip this extra feature right now, because it requires some additions
to each model.

I will catch a Spectre manual to figure out what they offer here.

Holger