How can we improve WHMCS?

we need to have the ability to assign Sub Tasks that can be checked off within tasks

so for example let say we have a task called "Domain Transfer" under a web development project for a client.

we would then need a task that can be assigned and checked off for Obtain EPP Code, another one for initiate Transfer, another one for Update DNS once transferred.

this way we can have specific tasks handled by different staff within an overall general task but within a project.