Please check the section New Versions of External Purchasing Documents in the following link
Version Management - Purchasing (MM-PUR) - SAP Library
According to this link,
Only the following changes lead to a new version:
- All print-relevant changesYou define which changes are print relevant in Customizing for
Purchasing
under![Start of the navigation path]( "Start of the navigation path")
Messages
![Next navigation step]( "Next navigation step")
Fields Relevant to Printouts of Changes
![End of the navigation path]( "End of the navigation path")
. - Changes in document assignment
- Changes in address
Please evaluate my inputs in a test environment.