As a custodian, you've established secure signing procedures and technology to keep client's assets safe. Since Staked is non-custodial, you can keep client assets just as secure while allowing them to participate in on-chain activities like staking, governance, et al.
Use the Yields API to share what's available with your clients. When they are ready to stake, Staked will provide you with a chain-specific delegation command. You will sign this using any security method you've established. You can then broadcast to the chain, or return to Staked and we will handle it. The Reporting API can provide you with details on the Rewards your customers have earned, making it easy for you to keep them updated.