If I remember this right, d-formers didn't work right in DS3, and even in earlier versions of DS4. I don't remember exactly what was wrong, but I think DAZ was figuring out how to implement them in DS. I remember in one of Paul's tutorials, he tried to use d-formers to make a quick test morph, and they didn't work right in DS4.7 either.
But they are compatible with Poser magnets, and that makes sense, since the entire Millennium 4 figures used magnets in their internal rigging. The magnets were hidden so people would 't see them, but they are there! And consider Vicky4 was, and perhaps still is DAZ' most successful figure to this date. ^^
So magnets can also be used for figure rigging, but I just use them to create morphs. One of the huge advantages of making morphs with magnets is that they can be changed at any time if you save the magnets to the props library. This allows creating several variations of the same shapes on the spot by reapplying the magnets and spawning new morphs out of them. In the beginning, magnets could only affect a single body group, but now they can affect as many groups as you wish, and Poser allows controlling their influence with weight maps, giving us vertex level control.
I have been using magnets to create body types for years, but now I am delving into creating facial morphs with them, which is especially challenging because the head is made of many separate parts, and it's easy to mess them up. ;p