OK, great news! Please specify which of the mods (1,2, ... 7) has been successful? MOD3? (I will update the first post) Thanks for the feedback !
Yes, it was Mod3 that worked. Just put the modded BIOS in USB drive and used EZFlash from the BIOS menu. Afterthat, ran the Opatool and chose ASUS-NEW certificate. Thanks again.