The usage 3 (and supposedly the usage 4) includes the state opposite to 'Shusseken', i.e., the state of being wrapped in 'Seken', which shows that the general usage diverges from the original religious meaning.
3.（或いは4.も）から来た用法は逆に世間に埋没している状態を含み、元の宗教的意味と一般用法との乖離が生じてしまった。