Developers had to unlock the bootloader—a notoriously difficult task on OPPO devices—to install custom recoveries like TWRP. They then adapted ROMs originally built for similar MediaTek-based Xiaomi phones (like the Redmi Note 4 MTK). The "Frankenstein" Experience Running MIUI 8 on an F1s was a mixed bag:
: Creates a separate profile on the phone, effectively giving you two "homes" for privacy. miui 8 oppo f1s