Custom hardware with companion app, question with Subscriptions

I have a question regarding in-app purchasing and subscriptions for an app that interfaces with a custom hardware product.

Say there is a custom electronic product that communicates over BLE to an app. The custom hardware is sending different types of sensor data collected on the device to the ios app and that data is stored on a backend.

If the mobile app plans to have a paid subscription, but still allow users to use the app without a paid subscription but simply limit access to view some of that collected data (for example, locked/greyed out screens or limits features available in the app), does that fall under the IAP requirements of Apple?

In the described case, would Apple mandate the app use the App Store's in-app purchasing system and take the 15-30% cut for the paid subscriptions? Or does that not apply since the data is collected by a custom hardware product?

I am a little unclear on this. Any guidance would be appreciated.

Custom hardware with companion app, question with Subscriptions
 
 
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