Deployment from development to test using a different external database extension

Good morning,

We're developing an application that connects with an external database through an extension.
For now we have 2 environments (development and test) and 2 identical databases for the corresponding environment.
We are linking the application with the database through the use of an extension and, as we have 2 environments, we configured 2 extensions.

Our problem arises when we deploy the application from development to testing environment and try to update the application's dependencies. 
We want to drop the development database extension and start using the test database extension, so that the 2 environments are completely independent.
When dropping the development database extension, Service Studio crashes and we can't configure the new dependency.

We want to know:
- if there's a better way of handling the connection with an external database (e.g. through the use of only one extension, or any other way);
- if there's another way of deploying the application from one environment to another which could prevent these issues;
- if there's a way of avoiding Service Studio bugs and crashes while updating dependencies.

Best regards,
David

I tried using just one extension and then changing the Logical Database to point to the correct one.

But it seems that the connection is always defined to the schema I choosed when importing the entities in Integration Studio.

Is this a bug? Or am I doing something wrong?

That's it, thanks a lot.