Customise roll up for standard fields

Would be nice to be able to change the roll up criteria (for example, based on Task state) for the standard revenue and cost fields to allow for various conditions:

- Allow for "Requested" tasks to not roll up for the budget (to plan for tasks without impacting budget) since not showing up in resource planning.

- Allow for "Cancelled" tasks to roll up for Actuals (so actual time spent isn't missed or ignored by Project managers)

I think there is already a request for being able to create new project/task states so this request is to be able to customise the standard fields to allow for more usage (rather than having to create an entirely new set of custom fields)