Lowering CPU freq at boot

#1

Using the Rock 4B+, I want to lower the max cpu freq of the big cores at boot. What I was thinking of doing is creating a .sh script with the line
echo 816000 | sudo tee /sys/devices/system/cpu/cpufreq/policy4/scaling_max_freq
And then creating a systemd that calls this script file at sometime just after booting. Is there a better way of doing this? Is there some .config file or other script that I could edit that would make more sense?

#2

If You can set higher freq for rock4 board with overlays then it should be possible to lower max frequency with same thing. Make backup, decompile Your dtbo, make changes and compile again.