" ( Hint: some might remember the feature .... Computing magnets in world space ) how many of you do understand this feature and why it is a part of Poser ?"

Which feature? Compute magnets in world space? I've seen it. Properties tab, Body actor, below the conforming options. I'm woefully under informed about magnets, in actual practice, at this point in Poser tech I've never had the need to use them other than by force using legacy figures equipped with such Deformers. I vaguely remember using magnets for morphs in Poser 6 or 7 I guess. What's your point? The Daz figures being rendered inoperable in Poser?

Apparently some problems with V4 regarding back in the day...

https://www.daz3d.com/forums/discussion/24018/poser-pro-2014-carrara-8-and-victoria-4-2