I don't think it is easy to enable, but it is certainly possible. Here's an
idea: If InfoPath has to get data from the previous form every time a new
form is created, you can create a table in SQL Server for example to store
the data (that you need to load when a new form is created) whenever a form
is saved to the Forms Library. So when you save a form to SharePoint, you
also save the historical data to SQL Server. And every time a new form is
saved, you just overwrite the historical data in SQL Server, since you only
need to retain the last saved data. Once you've got this working, you can
write code in the OnLoad event handler of the form to retrieve this data
whenever a new form is created and load it into the form using either code or
an XSLT.
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S.Y.M. Wong-A-Ton