LineageOS is often considered the gold standard for older devices. While official support has long passed, active, unofficial, and stable builds of LineageOS (based on Android 6.0/7.1) are available on developer forums like XDA.
Battery drains slightly faster than LineageOS due to extra features. Verdict: Best for power users and tinkerers who want the most control over their Oppo A37f. rom oppo a37f android 60 top