I've seen two advantages with a fan on the BGE. First is that it will get you to your target temp more quickly. Second is that it will help with recovery or quick adjustments (such as setting up to finish a reverse sear). You're correct that the ceramic cooker won't need much attention to hold a given temp, and a good servo/damper system is more than enough for the slight adjustments necessary - thus the suggestion by Ralph and others to use the "on at max only" setting for the fan in certain applications.