Mambu Core banking engine at presents seems like it doesn't pay interest on balance available in the dormant accounts, nor system posted credits seem to be allowed. Not all banks follow this logic, especially banks in India, UK do pay interest on dormant balances based on my knowledge.
Mambu can enable an additional feature if not already available - The ability to define a parameter for the banks to choose whether to pay interest or not to pay interest for balances in the dormant accounts. May be a value addition for the product.
Reference: https://support.mambu.com/docs/deposit-accounts-life-cycle-and-states (Section: Dormant)