It seems there is quite a significant bug in Rack Pro 2.2.0 that prevents audio drivers other than DAW being accessible to the Rack plugin.
In Rack 2.1.2 I can access my Mac’s Core Audio driver (and therefore my Expert Sleepers) directly from the audio module in the VST2 plugin. In 2.2.0 that Core Audio option is not available.
I reported this to VCV this morning but am posting it here as it seems quite a lot of people are wondering what is up and wasting their time / pulling their hair out trying to get access to their Expert Sleepers etc from the plugin - particularly PC users for whom it is not easy to get that set up even when Rack is working properly - which it is not…
I had to revert back to 2.1.2 to get access to Core Audio and Expert Sleepers again from the plugin.