General equality constraints for closed loop kinematics

[MaximilianDio]

Hello there,

I am currently looking into planning for closed loop kinematics and I am a bit hesitant to use MoveIt for this project - it is quite complex to only test a few ideas.
My goal is to plan a path for a dual-arm system with closed loop kinematics, i.e., cooperative dual-arm manipulation.
Although I have seen that there exist equality constraints for position, orientation, I was not able to find a general constraint i. e. c(q)=0. In the simplest case the relative position of two end-effectors of two robots are fixed r_1(q_1) - r_2(q_2) = const. It becomes a bit more complex when you incorporate the orientation but for now not of importance.
I have looked in the way MoveIt implements the EqualityPositionConstraint and I think it makes sense to start from there as a reference but maybe there are already projects trying to incorporate these. If so I would be grateful if you can reference them here.
Do you think it is reasonable to start with evaluating thin is MoveIt or would you recommend to work directly with ompl?

Regards,
Max