You only need demand to fill XYZ Berth & then you can run train as non-stop (is that demand exist?)!! Various Booking legs get created, not just in GEN but PQ/RLGN also. Even with presence of various legs, WL is presumed to be from source by most bloggers!!
Booking is opened for JYG/DBG/SPJ from day one & none stop JYG to completely fill its allocated Quota!!