For some use cases you can use the Note Analyzer in SNOTE to validate if all the relevant OSS notes for that specific function are applied with the latest version.
OSS note 3200109 – SNOTE : Note Analyzer contains PDF with the full user manual of this tool.
The short manual is: start transaction SNOTE, go to menu Goto / Other Tools / Launch Note Analyzer.
As example we take the xml file from OSS note 3365856 – Note Analyzer Input File for SAP Readiness Check for SAP S/4HANA upgrades as input. Now press the Analyze button. Wait and analyze the output:
Here you can see some notes are still needed to be implemented and/or updated with newer version.