If an item can't be stored in a hold, can a ship use a tractor beam to tow another item or ship during warp?
I'm thinking of the case where, perhaps by design or through battle damage, the saucer section cannot be reattached to the rest of the ship. Without its own warp drive the saucer section would be required to make its way to a suitable repair/docking facility without warp drive unless there's a way to tow it, or reattach it firmly enough that it can withstand the forces it would have to endure during the trip.