Is there any documentation that describes this behavior in detail? I would like to scale my timers based on the scan duration, but I would rather not just use trial-and-error to find the times

Nope, it is in the foreground, and the screen is not dimming, and there is no split screen being used.. This is only after a couple minutes. As said above, the issue goes away if I keep stopping and starting scanning every 10 seconds, so it is unrelated to the app foreground/background state, iPad sleep state, or split screen, as the app was in the exact same state in both tests.

That sequence of steps has worked just fine for me when I'm building an app target in the same workspace. I want to be able to hand off the signed .dext to a completely separate project or group to embed.