How to copy a model within the same service - is this possible?

I am configuring a new Master Data Services 2017 site. I want to have 2 models on my site - one for test/dev work and one for Live data. I created my test model (let's call it MyModel_TEST) and added some entities and data. I then wanted to create a copy of that model, just called MyModel, by using the MDSModelDeploy utility.

So, I first exported my model to a file using the createpackage switch like so:

MDSModelDeploy.exe createpackage -model "MyModel_TEST" -service MDS1 -package "C:\temp\MyModel_TEST.pkg"

Then, I ran the following command to create my copy model:

MDSModelDeploy.exe deploynew -model "MyModel" -service MDS1 -package "C:\temp\MyModel_TEST.pkg" 

However, this results in an error, which is:

MDSModelDeploy operation failed. Elapsed time: 00:00:48.5553101
Error:The "MyModel" model cannot be deployed.
1750: Could not create constraint or index. See previous errors., @ErrorNumber = 1750, @ErrorProcedure = "", line 2, @ErrorNumber = 50000, @ErrorProcedure = "udpEntitySave", line 916
Correlation Id: 7bf9f0ce-d030-4c21-843d-f9920d1c900d

I also ran a SQL Profiler trace to capture more detail and noticed there were several other errors, such as:

Invalid object name 'mdm.tbl_5_52_EN'.

Am I trying to achieve something that is not possible with MDS? Is there a better approach to having a separate test and live model?