Rob, do you have background loading enabled? That'll return control back quicker, although it means you won't always know when the libraries have finished loading.
As a completely irrelevant aside, I'm currently working on a project that's Kontakt-heavy. Being a new computer, I don't yet know what its limits are. But I've currently got 9 instruments loaded, 3 of which are monsters. There are also 2 instances of Keyscape in the project plus Ozone and ValhallaRoom. It takes a good 2 minutes to load the project (from a conventional, non-SSD drive), but once loaded it sails along smoothly. Even when I forgot to set my buffers back to mixing size. How much of this performance can be credited to Kontakt's efficiency, I don't know. But it's making me pretty happy.