To me one thing seems clear, that when heaven is opened only God can shut it! Once the wall between dimensions has been torn, then it is easy to break through again.
In the Celtic tradition of Christianity these places are called “Thin places” Columba’s Iona, Patricks Croagh Patrick The cliffs of Saint David. and more, but I am led to believe that these places are thin places because the glory of heaven has once been opened there and it is easy to break through again.
Evidenced I think in recent times by 1904 Welsh revival (St David) 1950,s Hebrides revival (Columba) 1920’’s Jefferies Bros in Ireland.(Croagh Patrick)