I communicated with the support team, and I understand there are currently no endpoints that include the below information, which is necessary for reporting the transactions correctly.
Using the Binance Lending/Savings API endpoints, I am extracting the subscriptions report, however there is no way to distinguish between an actual subscription to a fixed/flexible/customised fixed product and a transfer from e.g. the Binance spot account to the Savings/Lending account. They are both shown as normal subscriptions, which is obviously misleading and results in misreporting.
Also there is no endpoint to show subscriptions that have been “renewed”. When logging in the account, there is a subscription type column which can be “Renew”, “Transferred” (as per point 1) or “Normal”. It is necessary to have endpoints showing whether a subscription is renewed, or when the subscription shown actually refers to a transfer (as per point 1).