BQ export from GA4 rollup appears to retain sessionIDs from the source properties

[DorcasAatCAT]

When pulling data from BigQuery for a linked GA4 rollup property, the sessionID appears to be retained from the GA4 source property. We infer this because the sessionID varies as a user proceeds from one hostname to another hostname.

The same user data has only a single sessionID in the BigQuery data for a linked UA rollup property - the sessionID never varies across all the different hostnames. This enabled us to pull UA data easily by sessionID.

Unfortunately pulling similar data in GA4 is now extremely cumbersome and requires a complex workaround. For some scenarios we anticipate there may not be any feasible workaround.

Will GA4 be providing a consolidated sessionID dimension (possibly named something else) for export to BigQuery in the future?

We would expect there to be a consolidated sessionID for rollup properties, either replacing the source property sessionID when exported to BigQuery, or populating a unique new rollupSessionID dimension when exported to BigQuery.