Dear Kurt Miller,
Thank you for your suggestion! We'll discuss the possibility of adding such feature to our feature request list.
Anyway, we can offer you two solutions that can be developed in near future:
1.Task Manager Pro has custom fields where you can add your own fields and choose their types, ex. text, numbers, dates, etc. we can add one more type: Resource List, so you will be able to create a field and name it "Responsible" and then choose from the list a resource who should be responsible for task.
2. In Edit Task Dialog, in the tab Resources there will be "Combo box" field where you will be able to enter the name of the person who will be responsible about the completion of the task which assigned to executor of this task.
Please tell me which variant is more suitable for your needs.
Best regards,
Victoria