Compact reduction in Lipschitz-free spaces

We prove a general principle satisfied by weakly precompact sets of Lipschitz-free spaces. By this principle, certain infinite dimensional phenomena in spaces over metric may be reduced to the same free their compact subsets. As easy consequences we derive several new and some known results. The main results are: $\mathcal F(X)$ is sequentially complete for every superreflexive Banach space $X$, F(M)$ has Schur property approximation scattered $M$.