Can a Dev verify that the bagball blocking in the new dungeon is going to be allowed still like in invasion towns?
That tactic will no longer work. The captains will actively destroy anything that blocks their path and the normal rules applied to blocking a mob's path are as you would except them sans the invasion (to say, it is not allowed). The reason we lightened up for the invasion was two fold. For one thing, we didn't want to risk the destruction ability in an area where there is housing (New Magincia) and also we wanted to give the ability build barricades and the like as a means of "defending the city".