No, pages that return a 404 error will not be picked up by the Onsite Optimizer, and they will not editable by the Onsite Optimizer, either.
Will 404 pages be picked up by the Onsite Optimizer?
Updated over a week ago
No, pages that return a 404 error will not be picked up by the Onsite Optimizer, and they will not editable by the Onsite Optimizer, either.