User Profile

Hello, I've been trying to figure this out for days now. My app allows users to purchase a renewing subscription which unlocks premium in-app features. However, one device can also have multiple user accounts. If a user purchases a subscription on one account then logs into another account on the same device, that account must purchase a subscription too to access the premium features. Basically, the accounts are not tied to the device, or an iTunes account. From what I've read, StoreKit does not seem to allow this.So, I have thought of integrating a 3rd party payment system like Stripe. This would work but the Apple guidelines do not allow anything other than IAP if your premium features are in-app.Is there any way I can do this?

If a user requests Apple to give them a refund for a subscription they purchased, will Apple grant them this? Considering that they subscribed and maybe forgot to cancel. If Apple does refund them, do they take it out of your app's revenue?