Exclude children from parent summary

NavyPilot

It would be helpful to be able to exclude children in the date rollup of a summary task. In my example, I have checkboxes that select is a child is part of a summary task. The child has start and end dates. If not part of the summary task, the checkbox is not checked but the start and end dates are still used in determining the summary start and end dates.

Would be helpful in being able to exclude the unchecked children from influencing the summary task dates. Either through a formula (examining the checkbox status) or some other way.