[quote user="rrlagic"]
My guess is that project referencing works only for projects within workspace, but does not work for other path.
[/quote]
You are correct that referenced project should be within the same workpace. Given that, these are options I see (although there may be other solutions that are not coming to mind or that I am not aware of):
1) Users will need to import both the platform project as well as application project into their workspace so if the referenced project needs to be rebuilt, it can be
2) If platform project will not be used/changed by other users, instead of making it a referenced project, simply use the platform in the application project and add the path to the platform as an additional path to the RTSC repositories
3) As mentioned by Sasha in the thread you referenced, you could put the platform zip file (which contains all the files needed to use the platform) into source control. So, the users could check out the zip file, extract the files and use the platform without building it (in a way similar to #2).