Make 17213/14 NS NSL (Via WL) Daily and remove 17231/32. For GNT to have connectivity to SNSI run 17206/08(4 Days) in the route of 17231/32 and make 07417/18 a regular train and extend it to SNSI in the Thursday slot of SC SNSI. So there will be no loco reversal for 17206 at BZA and GNT will have 6 days connectivity to SNSI.
17213/14 can be speeded up by giving 12 PM departure at NS and 21.40 Dep at SC, then the incoming 17256 will have ample time for SM at NS.