Is it possible to set contact attributes for created tasks using streams API?

[bml1g12]

I'm aware with the https://docs.aws.amazon.com/connect/latest/APIReference/API_StartTaskContact.html API it's possible to set contact attributes, and I'm aware the streams library does not support setting contact attributes, but just wanted to confirm there's no way to set contact attributes alongside a agent.createTask operation?

Aside from contact attributes being useful for contact flow logic, they are also useful because when a telephone number is provided with a plus extension, they automatically format it as a click-to-dial, and as far as I can see that's not possible via agent.createTask references