It seems that you need something like project suite configurations. I have registered your request in our database, thank you.
The best solution I can suggest is using several project suites. Please note that you share the same project among several suites. So, you can add your Install and Common projects to all your project suites.
However, this does not solve the problem with project suite variables. To workaround this restriction, you can store the needed values in a separate storage file (e.g. a CSV or Excel file) and load information from this file to project suite variables at the beginning of your tests. For example, you can set the Common project to be the first project in all your project suites and the only test item in this project will read the needed data from external storage.
Please let me know if you need help in working with CSV or Excel files.