Hi Sivaprakash,
Don't quite understand your question/concern.
First of all, the PB IDE and runtime have been separated for quite some time now. So single PB IDE version could target 2022 R1, 2022 R2, and even minor builds of R1 or R2. You just select from dropdown and compile. So I don't see any significant risk that you upgrade to 2022 R2 because you could always recompile your app for R1 if problems.
With that said, anytime you roll out new app runtime version (not IDE update) into production environment it is important to do comprehensive testing before. Maintenance releases are less risky, but for a revision (e.g. R2) and especially major new versions you should test. As John said, it's your choice but definitely not a best practice.
As far as what has changed between R1 and R2, please refer to the new features guide: https://docs.appeon.com/pb/whats_new/index.html
Best regards,
Armeen