Suggested by Seema Tyagi – Needs Votes
Virtual Entity is not available for segmentation and personalization of email in Dynamics 365 Customer Insights - Journeys.
Multiple external data source data need to be used in DCRM, so using virtual entity can help pulling out data from externa data source and can be accessed in DCRM Segmentation and personalization of email, without storing the data in DCRM.
Make Virtual Entity available in DCRM for segmentation and personalization of email.
This feature will save storage cost for the customer.