Oppo F21s Pro Custom Rom (LineageOS)
how to flash?
1. Unlock bootloader with mtkclient
  • MTKclient  V1.52: Download
  • MTKclient (old): Download
  • NEW USBDK Driver (Latest Version dropped support for LIBUSB) : Download
2. Extract the zip file
3. Flash with SP Flash Tool
Important Note: 
You must to flash the ROM. If consultance only super + userdata or any other part, it will not work. But, because it should flash  the ROM - it locks the bootloader ...
4.You can Re unlock bootloader with mtkclient
5. flash empaty vbmeta.img
Known Bugs:
1. Most of functions need to use with touch screen
(You can install qinpad to type with hardware keys)
2. System is read-only.
I packed the super.img as read-write, but it did not work
3. No access to partition / DATA by Twrp
4. Backlight always on the keys (thanks to gaugga from 4pda)
5. can't use Bluetooth headphones
6. can't use headphones (to patch headphons
Phh settings > Misc > Use alternate way to detect headsets
and reboot.

Download - LineageOS