In the console, type $$ and press enter. Check the number next to the $30 setting. Then, in LightBurn, go to Edit > Device Settings, and make sure the ‘S-value max’ setting is set to the same value. If it isn’t, that can affect the power output.
You can also click the ‘Additional Settings’ tab in that same window, then click ‘Read from controller’ to have LightBurn apply the motion settings from your machine to the simulation, which can make the time estimates more accurate.