F2FS flashing Guide
1. Flash any f2fs supported recovery (if already have then no need.) Download
2. Boot into recovery mode
3. Wipe system, vendor, data, dalvic & cache
4. Flash rom
5. Format data by typing 'Yes'
6. Go into wipe section & select Data then advanced then select F2FS
7. Go into wipe section & select Cache then advanced then select F2FS.
NB: U must flash rui2 firmware 1st..check group for that.. If u already on f2fs partition then U can skip 6, 7 option..