this post explains possible options to export and migrate data from one specific customer (one origin) from a MSP environment to an on-prem environment.
1. Use cmdgtw probe to export data from 1 origin => this just covers the data export.
2. Direct export from SQL studio of the following tables (filtering by origin):
S_QOS_DEFINITION, S_QOS_DATA, RN_QOS_DATA tables
Then, re-import them in new DB before inserting any data into new database.
3. Move the full DB and then clean-up data that from other origins.
4. Install a complete new standalone environment in paralallel and let the customer keep using the MSP environment for old data reporting.
5. Stand-up on prem Core and Scale Tier hubs, double-post msgs to MSP and the new Core hub for some time. Eventually turn off the posting to MSP environment but keep old data for reporting needs.
Note that options (4) and (5) are probably the best from an effort perspective.