Here is the CX F-class service note.
2 Class Service Only on 74A (55C/324Y) & 77A (63C/238Y) :
- Japan ( SPK / NGO / FUK + TPE/KIX tag )
- S.E.A. flights except MNL / JKT / BKK / SIN direct service + HKG/BKK/SIN vv
- Mid-East flights except BOM / DXB direct service
- China flights
So other than above, all Asia flights by 744 and 77W provide F service ^