Some of the links on this forum allow SMF, at no cost to you, to earn a small commission when you click through and make a purchase. Let me know if you have any questions about this.
Can't speak to the large smokers, but I have an MES but don't use chips & use sawdust in the AMNPS.... Reason I personally do this is the chip tray in the MES needs reloaded every 30-45 min & the AMNPS with the sawdust lasts for hours.... Some folks can also use pellets in the AMNPS but due to my elevation I have to use sawdust !
Commercial smokers use an automatic feed system, augering out the correct amount of sawdust into the pan from the hopper at predetermined times. Chips or chunks would clog the system.