Migration of Standalone Splunk Enterprise from server on version 8.2.2.1 to server on version 9.0.8

[PComSplunk]

We are currently looking to migrate our Standalone Splunk Enterprise server from the existing ec2 to a new ec2. The new server will be based on AWS Marketplace AMI for version 9.0.8: https://aws.amazon.com/marketplace/pp/prodview-l6oos72bsyaks?sr=0-1&ref_=beagle&applicationId=AWSMPC...

Reason for migration: we want to use the Marketplace AMI while upgrading the Splunk Version

Since this migration involves going from version 8 to version 9, just copying over the apps(they contain the indexes) hasn't given us the result we wanted in our dev/test environment. We end up with no search UI loaded when the search app is copied over from the previous version 8 server to the version 9 server. 

Has anyone else migrated their server this way i.e. jumping versions while migrating to the new server?

What would the community recommend in terms of a scenario that we currently have? Would an in place upgrade to version 9 and then copy over to the new server be a better option/recommended? 

[richgalloway]

I would recommend an in-place upgrade to version 9 and then copy Splunk to the new server.

In general, one should not copy an entire built-in app (like search) between instances.  Transfer only the local folder.