AFAIK for SoapUI versions up to 1.8.0, the calltestcase step only supports calling test cases within the same project.
We have hundreds of utility test cases in a large project with ~1000 application level test cases that use them. We also have another project containing tests that need to call the same utility test cases. Currently we have to maintain two copies of the utility test cases because the second project cannot call into the first.
Instead, we would like to have one SoapUI project containing the utility test cases, and multiple other projects containing the application level test cases that call into the utility tests. Then we would not need multiple copies of the utility test cases, which is a maintenance headache.
So we'd like to request a SoapUI enhancement to support calling test cases in other projects. That would reduce our maintenance efforts considerably.