Don't have your machine in custody but on our two Kubotas in 35-40-hp range the temp rarely gets to half-scale. Usually runs at 25%-33% even in hardest work in extreme summer heat.
If I see the temp climb even a little I know it's time to clean the radiator and / or screen. We keep a cheap $1 HVAC filter ahead of the prescreen. When temp goes up just pull it out and put in new.
If washing radiator used hose without nozzle from both directions. Too much force will bend fins quick.