Hello, excuse my bad English, I'm Italian.
I saw that you are experienced with inverter gti. I have some gti (gp-350)
the controller is a ucc3806, I would change the maximum output power.
inverter 48v battery powered, has 250Watt output, I would bring its output to 200 watts so that less warm. you think you can do?
then with 5 gti can insert them one at a time 200 + 200 + 200 +200 +200 = 1000watt
thanks
Luca
I really would not worry about how warm it gets unless it was really poorly designed and runs untouchable hot but then there is no help for bad design either.
If you want to limit the peak power level all you need to do is limit the input power. The unit itself should take care of the rest.