Help Best time to change rope length?

[protomenace]

Is there a preferred time in the game/physics loop to change the length of a rope with an ObiRopeCursor? Is there a time at which it would be the least disruptive to the Obi physics simulation?  For example, will the rope be better behaved if I were to update the length of the rope during an ObiSolver.OnSubstep callback? Or maybe just during FixedUpdate? I assume changing the length of the rope in Update() would be quite inconsistent and maybe cause some weird behavior relative to doing so as part of the physics loop?