I think you have the same coop/run that I have. It's perfect for this kind of thing. My coop is right out side of a glass door next to my desk, so I can keep an eye on them when they are in or near the coop. I give mine a treat tossed in an exercise pen that is attached to the coop. This is an additional XPen made for dogs that I attached to the original coop/run. I toss them treats in the outer pen, and then close the pen's door to keep them from free-ranging. They will go inside the coop's run and head up the ramp sometime around dusk, and I close the pop door for the night. When it's really hot, I keep that pop door open for ventilation and just keep the metal attached run door closed and latched. I agree that it's very secure to keep the pop door open when it's hot outside overnight.
Once when I was at a meeting and would be home after dark, I left them in the outer pen, and when I got home, they were all inside the coop on their roost. I was so proud of them, lol! I just closed their pop door and the coop/run door, then the XPen door and they were buttoned up for the night.
I'd bet your hens did the same.
My girls free-range all day and we've have never had a problem with a predator yet, so I took a chance that one wouldn't come into the outer pen with it's door secured, and it worked out fine. I just posted a description of my coop and XPen with photos, if you are interested, this is the link:
https://www.backyardchickens.com/articles/my-small-coop-from-tractor-supply.78218/ You can see the "before," and how it looks with that outer run which gives the hens more room when they are confined in the "after."