The cooler thermostats are a fallacy if thought to lower actual running/loaded engine temps. The thermostat only sets the opening or MINIMUM temperature, not the running or max temp. Running temp can’t be changed without a larger radiator or at least delete the interference to smooth airflow like “shutters”, or by reducing the engine load, or by reducing the ambient air temp. Of course, if the air temp is in single digits your heater doesn’t feel so warm either unless you load the engine heavily. There’s no simple free lunch.
You can likely lower running temps by removing the thermostat like we did on racing engines back in the day, but in some cases the water moved so fast at high rpm with our tiny 2-row radiators that it didn’t have enough time to cool much. Such was life in the old(er) days.
Oh well, the only real advantage of a lower temp thermostat for our modern “performance” useage is to allow the engine temp to cool quicker after reducing the load from that loaded, normal running temp. That means when you beat it hard(!) and then slow/reduce load, it cools back down quickly as the minimum temp baseline is lower.