How to create subscription discounts for new users in a React Native app?

Hi,

We have just recently released a new version of our React Native app to the App Store that allows users to subscribe to a £15.99/month subscription. We have a big affiliate network which we want to tap into to drive sign ups. In order to do this we want to offer discounts to people who sign up using an affiliate discount code. From reading through your documentation on whats possible in Apple and Google we have come up with the following approach.
 

Apple App Store:

1. Create a new subscription group
2. Create 4 new subscription products
   1. £15.99/month
   2. £15.99/month with Introductory offer of ~30% off for the first 4 months (i.e £10.99/month)
   3. £15.99/month with Introductory offer of ~20% off first month (i.e. £12.99/month)
   4. £99.99 annual subscription

Google Play Store

Similar to what we have in Apple i.e. creating multiple products that have introductory prices

React Native App:

• A user will have the option to enter a discount code
• On submit of discount code we will make a API call to our BE that verifies if its a valid discount code
• Depending on what discount its is (i.e. 30% or 20%) we conditionally display that product to them so that they can subscribe

A have a couple of questions to this approach that we are planning on implementing:

1. Is this the recommended approach to do this type of discount for new users?
2. If a user cancels a subscription would they be able to re-subscribe to one of the other discounted products via the App Store Manage Subscriptions page? (We dont want to allow users to sign up for multiple introductory offers)