I’ve not attempted to tune cpufreq. Simply having cpufrequtils installed gets my systems running all cores at close to minumum most of the time. That is on AMD APU. YMMV with Intel CPU.
The issue is discussed in one current thread: https://community.ipfire.org/t/ipfire-2-29-x86-64-core183-issue-w-cpufreq/11090/17
as well as several earlier threads that you could search.