So, yeah. I'm blocked.
This app *does* use IAP, so I definitely need to be able to log into a sandbox account. But I'm trying to add iCloud sync for some saved settings & such, so I guess I need to use my normal iCloud account for that. This is using *iCloud Key-Value Store*, which I'm led to believe is somehow different from CloudKit, though I'm still not 100% clear on the distinction between all the different iCloud approaches. So I have 3 questions, now.
1: is it possible to use a Sandbox account for IAP at the same time as iCloud Key-Value Store? It seems like it should be, since they're separate settings.
2: what account is it asking me to log into on launch, and why can't I login?
3: Is there *any* way outside of adding a debug setting in the app to clear the Key-Value Store? Even though the data persists across deleting & reinstalling, it doesn't show up in iCloud's "Manage Storage"