A method of adjusting a processing parameter of a polymer is provided. The method has the steps a) and b). Step a) is combining polymer i) which is polypropylene and/or polyethylene with a process aid ii) to provide a polymer composition. Polymer i) has a peak molecular weight Mp and a polydispersity index PDI of 7 or higher. Step b) is processing the polymer composition at a processing condition. The processing parameter is adjusted at the processing condition for the polymer composition compared to a comparative polymer composition A); and a comparative polymer composition B). Comparative polymer composition A) lacks the process aid ii) but is otherwise identical to the polymer composition. Comparative polymer composition B) includes a comparative polymer having the same composition and Mp as polymer i) and a PDI less than polymer i) instead of the polymer i), but is otherwise identical to the polymer composition.