Following the KCL the sum of all currents entering and leaving the junction must be equal to 0. So tapping into the cables will almost double the current from the PSU to the tapping point. Aside from the fact that the strength of the electrical circuit is equal to its weakest point (the tapping point if it is not based on solid soldering) the cable part from the PSU to the junction becomes undersized. Much better solution is solid soldering of properly sized cables directly to the PSU terminals.