When a boat from Extra Boats is chained to a normal boat, the normal boat will jitter around/ rubber band when trying to pull the boat from the mod. I assume this may happen with other boats. This issue goes away if the world has been left while the player is still in the boat and reloaded.

I realized this just happens depending on which boat you drive (which the chain is connected to first), regardless of mod. I have closed this issue in shame.