So who says you have to use anything greater than Poser 10?  Keep with that version and all your great V4s and her add-ons work just fine.  The problem of course is that vendors would have to choose between V4 standard or Weight mapped which ever version that might be.  Since everything works in standard you can guess which version will get the support.  And I am sure that the small number of V4 forever supporters have no problem with doing the conversions themselves getting a new person to learn that is highly unlikely.  I haven't been over to DAZ in a very long time but do they really have a bunch of new V4 content rolling out the doors?  A couple of products here doing a quick lookup shows products for DAZ V4-Genesis 9 using I-Ray materials.  Not exactly Poser friendly. 

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13