I've moved from 1.0.9 to 2.0.0 (next version) and many breaking changes were introduced. In changelog (https://pub.dev/packages/in_app_purchase/changelog) I read this:

Deprecates the InAppPurchaseAndroidPlatformAddition.enablePendingPurchases()
but in README (https://pub.dev/packages/in_app_purchase) we have this:

if (defaultTargetPlatform == TargetPlatform.android) {
    InAppPurchaseAndroidPlatformAddition.enablePendingPurchases();
  }

Also it became extremely complex to be integrated now with so many files when I only needed this before:

class PaymentQueueDelegate implements SKPaymentQueueDelegateWrapper {
  @override
  bool shouldContinueTransaction(
      SKPaymentTransactionWrapper transaction, SKStorefrontWrapper storefront) {
    return true;
  }

  @override
  bool shouldShowPriceConsent() {
    return false;
  }
}

I only have a paid version and a subscription.

Also wanted to mentioned that I find these issues related to documentation quite often for important packages like this one or for google_mobile_ads:
googleads/googleads-mobile-flutter#461
#93316 (comment)
#89950

Changes on these 2 can modify earnings and cause bad reviews from users if that affects their accounts.