Have you delidded your CPU?
Having done multiple re-seatings and pastes I can confirm that it is currently as good as it will get. The paste spread is near perfect, which is why I am a bit confused here. It's the same cores regardless of cooler used.
Delidding is a bit outside my comfort zone, and I'm not sure if it's worth the risk for my use case. Not sure yet how heavy the CPU will be stressed during music / audio projects just yet, but I have a feeling it will get close to 100% by the end stage of big projects.
It's a 13600K, core 4 and 6 are the ones that usually are higher.