I’m currently using a SharedResourcePointer for communication between different instances of my plugin. As version 3 AU are supposed to run in different processes, I was asking myself if that is still going to work. Are all plugins of one kind running in the same process, or does every instance of a plugin get it’s own process? Just think about the memory usage, if every instance of a plugin loads all it’s resources into it’s own process memory again and again and again… good luck with that Mr. Steven Slate 
I think you basically have to assume that there’s no way to know whether a host is going to load one instance per process or multiple ones, so just have to deal with it. But this isn’t something that matters much, you can still write using SharedResourcePointers as if there will be multiple instances, and if there’s only one, then that’s just the way it is.
I guess in a situation where you really do have a ridiculous amount of shared data then the only way to deal with this would be to launch a shared child process for the constant data and make it create a shared memory map for all the clients.