It would be useful to see all the subtasks groups appearing when clicking on a task instead of just the current live subtasks group. This would be useful for lengthy workflows such as onboarding or accounts preparation tasks if several staff are involved in the task. For instance, for onboarding, some steps are not necessarily conditional to other steps being marked as done. The idea would be to have a quick overview of subtasks done and not done. So by clicking on a task, you would see all the subtasks groups with the number of subtasks done/number of total subtasks. Then you could click on each subgroups to see all the subtasks of the groups.
Also, if a staff member is allocated a subtask in any of the subtasks groups, it would be useful to see the groups, if they are allocated a whole group, or their respective subtasks highlighted in some fashion in their respective tasks lists. So they would see the tasks appearing on their tasks list and by clicking on the tasks which are not allocated to them, they would see the subtasks groups or individual subtasks which are theirs to do