The Oppo A54 is a Mediatek MT6765 Helio P35 powered device that ships with Android 10. A neighbor had forgotten her PIN in the process of keeping the kids off the phone.
This post is for educational purposes only. You are entirely responsible for your actions. User data will be lost.
Choice of tool
Although dongles like Hydra and UMT MTK support pattern / PIN unlock on this model, I chose MTK Client GUI because its free.
The first step was to do a full backup (excluding super and userdata) under the Read partition(s) tab. Next up was to erase the userdata, frp and md_udc partitions under the Erase partitions(s) tab.
After erasing these three partitions, I disconnected the device and held the power button till it booted up. It entered the setup wizard after a few minutes.
Why wipe the FRP partition?
After a factory reset, you’re likely to encounter a Factory Reset Protection screen if the device had been associated with a Google account. You can bypass FRP on Mediatek devices by wiping the FRP partition.