Cardinal does not load any external module binaries, the entire plugin is a single static binary. This is done on purpose for stability and resolving symbol conflicts within a single namespace. We believe this is the best way to operate an audio plugin.
There is an LV2/VST2/3/CLAP/JSFX plugin loader (Carla or Ildaeil) that can load audio plugins, but these don't sit directly in the Rack DSP graph and do not modify the Rack runtime like its modules do. You could load the VCV-Pro plugin and run it inside one of these if needed ;)
Cardinal is based on open-source modules (compatible with GPL3.0-or-later license) that are all compiled into a single static binary.
This is not possible with proprietary binaries.