If you don't cover the big holes somehow and some time occurs between the chicks hatching, the older ones will climb on the egg carton, eggs, or each other, through the big holes. I waited too long obviously, but didn't want to cool down the hatcher by opening it too much since some chicks were wet. Timing is everything. It takes practice in opening the hatcher lid and then the suet feeder lid in a quick motion.

My solution was to cover the suet feeder so that the lid can be opened. I did it with lingerie bag material and zip ties. Took a few minutes, but now in between I just hose it down and then wash it in the dishwasher, I've also sprayed it with a bleach solution and a few minutes rinse and then allow to air dry. It depends on how much time you have.

Be sure that the suet lid is closed tightly. Chicks can, and will, push the lid open and get out. Mine did.
My solution was to cover the suet feeder so that the lid can be opened. I did it with lingerie bag material and zip ties. Took a few minutes, but now in between I just hose it down and then wash it in the dishwasher, I've also sprayed it with a bleach solution and a few minutes rinse and then allow to air dry. It depends on how much time you have.
Be sure that the suet lid is closed tightly. Chicks can, and will, push the lid open and get out. Mine did.