Oh my, it just works now. I decided to continue trying to implement what you did into my own code for a custom solution, and now I finally managed to get decent results!!! :3
The IK-testrig isn’t the best (I have a better system but I just needed to test something), and it matches up surprisingly well with the active ragdoll:
As you can observe, it respects the limits like it should, and minus the small physical inaccuracies that I need to sort out, it is exactly what I wanted it to be. The best part is that I can control the strength per joint directly through the JointDrive, so I get direct control to the strength of the segments:
This is very most excellent. Thank you very much for helping me out and providing me with this source code. :3333