Though i have seen a similar request post, i am writing this to suggest few different ideas.
- Single relationship id with multiple accounts. Transfer between account are simple and happen in an instant. I know this is possible as i am using such setup with an other bank.
- Zero balance account with 0% interest. I feel like the regular savings account intrest is not much to me instead this amount can be channeled into offering better feature set. Higher atm limits, priority customer support, weekly balance sms maybe even better reward percentage, better analytics. This can be structured as a different account type for the customer to choose.