[firestore-send-email] Only works on (default) database

[BOXNYC]

I have multiple databases, “(default)” and “development”. I have firestore-send-email extension installed from the Extentions tab and another one installed from after I select the “development” database.

They are configured identically but it only sends an email when I add a document to the “(default)” database ‘mail’ collection.

When I look at the processQueue Cloud Function the extension creates, it has an Environment Variable DATABASE_INSTANCE that is empty. When I try to set it to "development" through the Firebase Console, I get an error "Users can't set environment variables, only the system can." (not verbatim)