[Rephrased and slimmed down as recommended]:
Apple suggests a method to avoid saving passwords in iCloud
backup by not creating an iCloud Security Code when KeyChain is enabled:
I'm wondering if there is a method to keep the passwords from propagating to other devices (as the previous article suggests it does) by, for instance, disabling KeyChain altogether. Would this keep passwords only on the device where they are set?
[Correction]: Apple says KeyChain is not stored in iCloud backup, just in the iCloud "live" data, so I've taken that bit out but the question stands...