Remember, sudden lamp inrush can cause the the generator to slow down causing it to go below 60hz. The result of dropping frequency actually causes the dimmers to to pass more power as they contain ramp modules that are tuned to 60hz. The effect can be pretty weird.
The risk is accidently going above 3.24KW, you should leave a buffer of 10%. If your powering moving lights you have to take into account the extra jolt of power needed for strikeing the lamp.