I made a test render with all the fur and long hair dynamics activated :D.
I got the long head hair to work, but only after I did a hair particle groom from new. It wouldn't really convert the new geo node hair method to the classic particle hair. In some cases, with the converted hair and if the character moved far away from their stat position, the hair would go a bit wild. And if you changed the frame without having calculated the hair simulation first xD.
Testing the hair did show I needed colliders for the ears, else the hair would get stuck inside them.
The next step was to see how stable the hair was during a animation, it was constantly moving, like it was underwater. I made some tweaks to the stiffness and did some weight painting for the hair, something that defines how mush dynamics should affect the hair. After further tweaks and simulation tests, it was moving normal.