Playground for Schema Changes
This is an enhancement for Schema Management & Deployment. It's attempting to additional Ops capabilities I think you can charge more for.
Possibly market this as a staging or "Playground" area for schema changes.
When the customer wants to "Deploy" this, they can trigger the Push-2-Prod action which
makes the changes Go-Live.
This feature will play really nice with the versioning of schema/data idea.
All together w/versioning, I think this is a feature you could monetize as an additional value-add of choosing HarperDB.