Air Assist - what downside to running it throughout the project

Hi there, I’m new to laser work and Lightburn. Using second hand a LaserMaster 2. I was told to use the air assist when ctting. I can understand why this needs to be used.If I were to leave the air pump running even while burning lines what effect would it have on the outcome? I can’t work outwhat downside its to running it for the whole project.