Prefilling a form programmatically

1. What is the general goal of the feature?
Allowing the users to call a method by form name or form id to prefill the form's certain fields programmatically
2. What are some example use cases for this feature?
If the app is integrated with pre-existing app, then from parent app, then the method could be invoked to prefill certain fields in form basis user inputs
3. What can you contribute to making this feature a reality?
We have used this method, but there are issues in XML rendering post prefilling, if the form contain < or > based regex.