Looks like I replied to the wrong comment.
The person you had replied to originally commented on not wanting to have the possibility of everything being broken by losing a single device. I think that's important that everyone realize that some sort of a backup plan is needed, whether that be back up codes, saving the original QR code, or being able to use multiple devices to authenticate.
At any rate, I should have replied to someone else. Sorry for any confusion.
Adaptive charging just charges at full speed until it gets to 80%. It then maintains that level until 2-3 hours before the time the alarm is set for, and then it charges to 100%. A 500ma charger likely wouldn't be able to fully charge the phone while a normal person sleeps (depends on the starting charge level of course), but the worst that adaptive charging wouldn't do anything that would lead to the battery being dead