I looked over my app's bundle locally using the codesign command which you showed me. I have not ever used that command, but thanks to it I could see details of the bundle's entitlements for several defferent cases.
I agree with your opinion that "temporary-expection" entitlements do not result from the QuickLook extension.
What I did and learned is that:
In spite of removing the QuickLook extension from my app, the "temporary-expection" entitlements remained in the bundle after building my app. (Build configration: Rerease)
Next, changing the build configration to Debug and building the same app, the odd ones were cleared. (In both, the same certification was used for code signing.)
From these things, I think there might be wrong settings in the Release configration of the Xcode project file.
Thank you very much for your useful advice.
I might be going to struggle to this issue for a while.