They will work if you measure each one to pick out the correct values(electrolytics have large tolerances), but the issue is of tolerance shift over time. In 10 years, the actual capacitance may have shifted enough to effect the response to an audible degree. It is much better to limit electrolytics to relatively low sensitivity parts of the circuit where large capacitance values are needed such as zobel networks. But for the actual capacitors on the filtering sections of the circuits, I recommend to use Mylar/Polyester capacitors. Madisound has a good assortment of this type. These are inexpensive and will not drift over time like the electrolytics.Would regular aluminum electrolytic caps (20%, with a high enough voltage rating) be okay for a crossover? Would the tolerance and/or type make any difference vs polypropalyne caps?