Create Return for Finally closed POS - is it suggestable?

Summary:

While we create PO return using Manage Supplier returns without Receipt , as credit note is not being generated automatically. Is there a way, Credit note can be generated automatically for returns without receipt?

Also, Can anyone suggest what will be the impact of opening a finally closed PO?

is it a suggestable process, of opening finally closed POs? particularly the ones that have been created 2/3 years back? 

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