I'm not sure how best to implement it, but it's not uncommon to have multiple people working on a project with multiple corridor files. Having just one itl for the project would cause a lot of conflict and possible erros so multiple itl files are used. The current configuration makes this more tedious since only one project itl can be made the default. So users have to constantly navigate to the itl they want to use.

Maybe the master itl needs to be more like a library file that brings in the template to the corridor file.