As mentioned in the other posts: loading a plugin in live operation is not something you should do - that’s also why there is no mechanism in Cantabile to do that.
The recommended approach is to:
- load all the plugins you will need in a song.
- use Cantabile’s routing to direct your MIDI input to the plugin you want to play
- use Song States to save different configurations of the routing from your MIDI input to the specific plugin you want to use (activate “state behavior” for the “target” property of the route from input to plugin)
- if you get into CPU load issues, you can also automate the “on/off” (run & bypass) property of the plugin - I usually recommend to keep all plugins on all the time and simply work with routes, since switching plugins on and off may create glitches, but it may be that some plugins create significant CPU load even when not playing notes.
- use bindings from incoming program changes to song states to switch between these pre-configured song states
Now you can use program changes to select which instrument you want to play with your MIDI controller.
If you have multiple song files that all use the same cluster of instruments, you may want to embed this whole mechanism in a linked rack:
- create a new linked rack
- load all your solo plugins into that rack
- create different rack states with the respective routing from the Rack MIDI input to your selected plugins
- create a binding within the rack that selects rack states based on received program changes on the Rack MIDI input
Now you can use this rack in multiple songs that may have different configs otherwise. This will make loading a song quicker, since that rack is already in memory from the previous one - and if you preload a setlist, this rack will only consume memory once.
A lot of this will only make sense once you’ve worked your way through @brad’s and @terrybritton’s tutorials, but once you get the hang of it, this would roughly be the way to go.