@Shadrach
Besides the auto pop door, another improvement could be: pavement around the coop and run or slabs / bury hwc in the ground. This helps against digging rats and other creatures for sure.
My run is in a condition that I didn’t trust for nightly predators too. Not wanting to get up early every day I decided to install a chicken guard to the run.
But last year a fox managed to enter the run at dawn (biting through a thick rope that held the netting).
One chicken went out after the pop door opened and got killed. Luckily I heard a lot of noise and went to see what was going on before he made more casualties.
Foxes hunt at dawn (and sometimes even during during bright daylight ) too. So for safety reasons it’s best to wait to open the auto pop door when the sun is up and the first people in the the street get up too.
In the 8 years the chickens stay in the run with a chicken guard I only had this one casualty by a fox and lost two chickens free ranging. Of course improvements against braking in followed.
The chicken guard itself never had problems except one time when I had a leaking roof and the thread got wet / got stuck .