Hey, Erika! Thanks for reply!
n1 - suggested generate feature is not the same thing, generate is good, but it affect whole mesh. It will require to delete unwanted vertices after generation
n2 - We used interpolation to transfer values of weights from one mesh to another. There is no need to have same position or amount of vertices in meshes, we can calculate everything.
Interpolation is simple - we need to take each triangle with weights values in vertices and than we can calculate weights value for each position inside this triangle, so we can use it for copying weights info. (hope it make sense for you)
I mean - we already have all values we need for transfer. You can see them in overlay mode.