MRU-JNB-CPT-JNB-HKG-CMB-HKG-BOM-HKG-JFK-YVR-DFW-ANC-DFW-YVR-LHR-DXB-LHR-JNB-MRU.

I know I have an extra segment to use in NA. Also the CMB and (I believe?) BOM segments have no first, correct? Are there better options from a mileage perspective that have first?

Help is much appreciated.