No. of lines in TAF do not mean anything. It's the TAF content.
4 or 5 lines with only wind direction change, we can still use VMMC.
1 or 2 lines but 500, 800 FG... VMMC will be affected too.
Don't count on the lines, count on the content.
CX TPE-HKG, if MFM is not available, next one will be KHH, if closure, TPE.
CX PEK/PVG-HKG, if MFM is not available, next one will be SZX, CAN, XMN.
CX other than china/taiwan, MFM, SZX, CAN, KHH/TPE, XMN/MNL