I ran across what installshield support calls expected behavior but I view as a bug. I wanted to report it here in case anyone runs into it.
User installs a suite project release. This suite project is uncompressed and user opts to not install all of the "features" or packages. Later, through Programs and Features, user installs any number of the remaining features.
In this scenario, the source for each added package can not be found. User is presented with a dialog asking for the source of each package being added. Apparently in compressed and Web type releases, the suite project will locate the source for all packages during a Modify or Repair operation. This is not true if the suite is un-compressed.
I had the support person enter a bug and engineering will evaluate the behavior. If anything changes, it will make its way into a future release.
I do not have a workaround except to use a web or compressed release.
For me, I can't compress my suite package since the resulting setup.exe file will be greater than 2 GB in some cases. I don't want to load that large of a file. The installation would take much longer than it should.