The same happened to me - I became too dependent on scripts from Dimension3D, Netherworks, and ShaderWorks. It became quite frustrating not having them in Poser 12. I was talking to Netherworks to see if he could do something, but he was being hired by a large company, and lost interest in Poser altogether. I have lost contact with him ever since. The only other guy I knew personally was Ralf Sesseler (D3D), but he had passed away a while earlier. There was literally nobody left.
It was a similar situation when vendors left HW, and there was nobody left to create the body shapes I wanted for Dawn - I had to do them myself. In this case, it just happens I was a programmer, and I was already moving to Python a few months earlier (due to AI developments and the end of Flash). I didn't know Python good enough to make scripts, but again, I didn't know sculpting good enough to create body shapes - but if I didn't do it, nobody would.
It was a steep learning curve, but it was worth it, because I saw it as an opportunity. It was yet another case where everybody left, and I had to carry the burden myself. In the beginning I really started to hate Python, but now I just love it for what it is. It doesn't care for industry standards, and does things its own way. It's a pain, but I have learned to respect it. As I predicted back in 2019, Python has become the most used language in the world, now surpassing even Java and JS. It has become a very valuable skill to have now, and in the foreseeable future.