I wonder if vertex weights are interpreted in exactly the same way by different pacakges, Lightwave, Max, CFX?
Not necessarily... LW has bones & weightmaps of course, but it also has several other options like followers etc that affect the final deformation of the vertices.
I think it is then down to exporters/converters to make the .B3D output look good, ie like it looks in the animating soft.
Of course you can support only subset of the features, and animators have to then use only the basics like bones & weightmaps. This might lead bit more complicated setups (more "control" bones & weightmaps) than "partially automated fixes" that LW for example has - but I would take "weightmaps only" option anyday, because without those it is just impossible to animate characters nicely.