Hi @Brian_Cohen, thanks for using GoodTask.
I assume you want something like 'Defer' or 'Hide until' on a task. Unfortunately start date doesn't work like that. Setting start date brings up tasks to be shown before due rather than hiding them. You can check below post for more detail.
https://forum.goodtaskapp.com/t/scheduled-smart-lists-with-start-dates
I'll keep your feedback on the list to consider. Thanks!