Hi weithh, have you tried

https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/system/power_management.html#dynamic-frequency-scaling-and-peripheral-drivers


This whole led control thing is not my top priority right now, i just noticed flickering of display backlight when ...

Just faced the same thing, but also noticed that when esp32 is busy with display rendering PWM frequency is fine.
Check your menuconfig -> component config -> power management -> support for power management. In my case after disabling it frequency finally became stable.

Also if someone can suggest ...