Consider when defining slack values you can define them for the control input, state, set constraints and non-linear constraints.

You need the slack values to be higher than gain Q-matrix so the controller will attempt to not violate them. This means that the controller will not violate constraints that decreases the cost function if violated. However consider the set constraint which states that an error must be inside a set, and furthermore consider an non-linear obstacle constraint. Ideally the set error constraint will have lower slack values than the obstacle constraint and the obstacle constraint will have higher slack values than the gain matrix. The effect I want is that that system will stay inside the set until an obstacle arrives which causes the relaxation of the set error constraint.

But I cannot see a way set the slack values deterministically. I know I could probably try my luck with the ordering but is there a documentation for this?