I moved away from V4 a few years ago now although I do still use the figure on the odd occasion.  Figure wise I use Dawn SE in any render that needs a female figure and I have not moved over to Le Femme because I content I like to use that simply does not exist for Le Femme.  I stick to one figure not because I regard it as a person or because I owe it any allegiance but because most of my renders are to support a story which revolves around a major character, which means I stick to one for consistency.  Changing to another figure is difficult for me and there has to be some benefit for me to spend the time making the change.

It is one thing to say that V4's entire library can be used by current figures but for a vast percentage of that I would have to ask why would you want to.  Due to their age few of the materials make use of the improved render engines and very few use dforce.  

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.