Defect in Process Model - For subprocess and start process smart service if we change assignment are able to add interface on Forms tab. What is the use of it ?

Question

For subprocess and start process smart service if we change assignment to :- This node will be assigned as a task to a person or a group of people 
 We are able to add interface on Forms tab. What is the use of it ? And if we change values in PV, changed values are not getting passed to child process. 
 Parent process variables have updates values. But child process has old values. (Not updated in this start process smart service Form ) Find document for reference. Defect in Process Model.docx

Kiran Sajjan · Answer

Need to update and make sure that PV should updated before start process or sub process. 
 Since the sub process or start process smart service executed before the forms action, so what ever changes done in that node it will not appear in the child process. 
 It's usually much better to separate out the User Input Task ahead of the next node to guarantee the order of operations. 
 even it's difficult to debug, if we combine everything together into single node.