Is that possible to directly manipulate vertices of a mesh using BPs ?

Hello, I am wondering if that is possible to manipulate/change vertex positions (using BPs) of a mesh which is created by a blueprint or imported. I am looking for that because I want to make kind of terrain editor rather than landscape. For Landscape I do not think in game manipulation is possible. Mesh, will have commonly used quad divisions. In addition, If that is better to use a ready mesh with grid divisions which file type will produce smallest size ?

This is possible using Procedural Mesh Components but I would caution you that landscapes are less flexible than ordinary SMs specifically because of how they are optimized, and attempting to figure the changing collision on a mesh with shifting vertices at runtime will not be cheap.

You might look into Runtime Mesh Component

Which is a third-party extension of the PMC which is more performant.