Some nights, I find my flock inside, other nights they are gathered around the pond, other nights they are waiting for me at the gate. Automatic doors would only be useful to let them out of the secured coop in the morning, you'll probably need to herd them in each night.
I'm in the same boat, considering an EZ-188 for my Muscovy ducks. I am planning on processing about 20-25 (mostly drakes) every 3-4 months and possibly renting the unit out to friends for their processing days also.