cle2000 customized ujb V2.0 (automatic undo jailbreak) which allows to revert to the Official stock FW of your region.
All credits to Liwil.

NEW in 2.0 : 
Method has changed => it is based on the automatical JB one, so bdpprog prerequisite file is replaced by official stock 65-0131 DECRYPTED FW of your region and reboot has been removed from the process.


Here are the required files (/mnt/sda1) :
- UDP20XRU.bin => official RUSSIAN stock 65-0131 FW.
- MAIN20X.bin or MAIN20XRU.bin or MAIN20XEU.bin or MAIN20XAU.bin or MAIN20XCN.bin or MAIN20XJP.bin or MAIN20XTW.bin => official stock 65-0131 DECRYPTED FW of your region.
(be careful : has to be valid, otherwise : brick !).

If all prerequisite files are present, the Official stock FW will be installed.
Your specific JB files present in /mnt/ubi_boot (as Overlay for example) will be kept even after the reverting to Original stock firmware. They will be retrieved if you decide to jailbreak again.

IMPORTANT : wait for the opening of the tray (which means the end of the process) before unplugging the USB flash drive!

A log is generated on the USB flash drive (/mnt/sda1) : revert_stock_ujb.log.

WARNING : if you leave the USB flash drive plugged into the Oppo and had previously already ran succesfully the ujb_stk_decrypted AutoScript followed by the jb_stk_decrypted AutoScript, 
i added a security check to avoid the 2nd launching of ujb_stk_decrypted.
This is logged and if you want to launch it again anyway, you just have to remove the log in the USB flash drive.

Do not forget to do a factory reset after the firmware upgrade.