How do I properly configure cpu power settings to not overheat?

I'm running Ubuntu 20.04 on a Thinkpad T14s. When I push the CPUs hard, i.e. with stress-ng --cpu 8 --tz -t 60, I watch the core temps spike to 90°C before I panic and stop the stress test. The fan will start eventually, but not nearly soon enough, and from experiments with lesser stress levels it doesn't seem that the fan will be able to dump enough heat anyway. I have had some good luck using thinkfan to make the fan more responsive, and that buys me some nice wiggle room at medium-high temps, but it doesn't make enough of a difference at those high spikes. I also installed cpupower-gui. It shows me that my system is already running in the powersave mode, with a max CPU speed of 4900 MHz. If I bring down the CPUs to around 3400 MHz, the system seems to stabilize quite nicely at about 70°-75° at full load with or without thinkfan. (It's a little warmer without thinkfan.) So, I've got a solution, but I'm unhappy with it; it seems that just permanently capping my CPUs isn't supposed to be the right answer. It is my very limited understanding that the intel_pstate driver is supposed to be implementing thermal control. I don't know how to verify if it is doing its job or not; from a functional practical perspective, it doesn't seem to be. My questions: is there a better solution than pegging the CPU speed as I've done? And am I better off running with more aggressive fans via thinkfan, or should I drop the CPU power further and stick with the built-in auto fan curve?