By thermal issues I meant electrical heating of windings in rotor,stator,transformer due to impedance changes with frequency.

I have only worked on one steam turbine and it had no issue running with the throttle valve wide open all day long.

Every system has a maximum continuous output capacity and I would expect the controls to limit the output so as not to damage the equipment.

I’m curious what sources you are aware of that can’t run at a maximum continuous output all day