Yes, yes, yes. Cantabile has Songs, Song States, Racks, and Rack States. Routes are like virtual wires that connect either Audio or MIDI devices. Racks contain VST instruments. I use Kontakt (Komplete) and so do many others here. There are special ways to set up Kontakt so that it won’t load samples except once when the program starts.
Think of Racks as hardware synths. You set up the VSTs and any effects, and create a Song State that functions as a patch on a hardware synth. Then you load up the Racks, pick the Rack States (patches) and you have your song. You can use Song States for example, to have piano VST for verses and organ VST for chorus. I don’t know what the actual limit is to either of these, but it very large.
There are excellent tutorials by Brad (the developer) and several forum members.
That was a very quick high-level overview.