We clarify the relations between sewing and propagating conformal blocks. In particular, we show that sewing and propagation and commuting procedures. As an application, we give a geometric construction of permutation-twisted modules for tensor product VOAs. Their first (algebraic) construction is due to Barron-Dong-Mason. The results and the point of view in this article are crucial for relating the (genus-0) permutation-twisted conformal blocks associated to a tensor product VOA \(V^{\otimes k}\) and the untwisted conformal blocks (of possibly higher genera) associated to \(V\), which will be discussed in an upcoming work.