I started creating a kinematics plugin for a new analytical inverse kinematic library  implemented by @Jmeyer. At the moment it seems to be working, but way to slow . It only does forward/inverse kinematics and you have to specify the geometric parameters in the
kinematics.yalm config file.
Overall, I had no idea what I was doing. I copied the template from the existing srv_kinematics_plugin  and added functions from another package  to interface with the inverse kinematics solver.
You can follow the progress by going through the issues on Github .
If anyone is interested in using this plugin, feel free to create issues or pull requests.
Thanks, @gavanderhoorn for suggesting this plugin .
(I think it could be interesting to add some MoveIt! tutorials focussed on writing plugins like this an others. But that’s a discussion for another topic maybe…)