G.fast is the most recent ITU-T standard for copper-based transmission, which targets at short distances and adopts a bandwidth of 106 MHz extensible to 212 MHz. In several scenarios G.fast systems will be composed by or coexist with uncoordinated lines, which are sources of strong crosstalk. This work focuses on evaluating an alien (out-of-domain) crosstalk mitigation method based on noise prediction that was proposed for predecessors of G.fast. Simulation results show that alien crosstalk mitigation methods can indeed improve the performance of G.fast systems, but under specific conditions. We have contrasted these situations and we provide guidelines about the feasibility of the crosstalk mitigation technique. As support for the simulations, we also present a set of alien crosstalk measurements.