Have you found a better alternative as you post your answer about canceling all subscribers every year?
In addition to 1-year subscriptions, the apple also allows you to fulfill other conditions, including 1-month subscriptions, for both renewable and non-renewable subscriptions.
Perhaps you can make your external interface in the application as if the user has signed up for a long-term subscription, but behind the scenes your application sends 1 month non-renewable subscription request for apple. Then each month, your application automatically requests another subscription for 1 month, and another ... just skip the months that you want to skip.
The user fills out the subscription form in your user interface 1 time. Your application logic remembers how many times to start a new subscription for 1 month.
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