The new importer addon does an excellent job. It not only works with a sibdivided genesis, but it also takes care of poses, expressions and other support files. The fitting also seems to be better as we were able to do with the conversion tools

As you said, it still is useful for those who use DS4 and Poser, but I think that will fade away as well since all DAZ content will probably move to DSON which is not supported in DS4. But I assume that those DS4 users who are interested in it, already have it. New users of the DS4/Poser?genesis combination will probably start with DS4.5 and Poser SR3

So I think you can probably retire it