I rough cut all the treads square to the same length, Then stack them together vertically and clamp well. Lay the track across all the ends, set the saw to the proper depth and cut all the return miters at once. Finish the cross cut with the Kapex and hand saw. The returns are all batched out on the table saw then miter saw.
I only glue the miter and do two pocket screws along the end grain into the return.