It would be great if temporary test users could be created without adding license nor creating new Azure AD users.

Sometimes admins don't have enough license to test as licenses they have are all assigned.

It's not desirable to purchase licenses only for test.

Users can get another new trial tenant for their test, but the test would not be sufficient because of solution relationship.

It would be much better if admins could create test user without adding license nor creating new user.

This would make Dynamics 365 (Online) more user-friendly, and they can test as much as they want.