You can now load VST plugins in Rack and modulate them. Big improvement for an anyways great and free software (Linking modules cost 30$):
If you don´t know VCV Rack – It´s a virtual modular system where you connect sound, effect, sequencer, function elements and such (100+) and build your own synthesizer. You´ll have to register on the website and choose/download these components through the software. Most of them are free, some can be purchased. VCV Rack can be combined/synced with other DAWs.
Here´s a beginner tutorial from BoBeats: