Hosting Audio Plug-ins, General Info?

Hello.
I am interested in coding to host audio plug-ins. Specifically, I would like to make a plugin to invisibly wrap multiple instances of another plugin, but I think this is just a detail.
I have the code from the Plugin Host from the JUCE extras folder, and I have also discovered the Element project.
There is also this short description, Part 2 of which addresses loading plug-ins.
Where else could I find some info on hosting plug-ins with JUCE?

My project would follow the example of Hermann Seib’s SAVIHost, but as a plug-in. So, if I want to wrap a plug-in called MyPlugin.au as a VST3, I would copy a VST3 version of the wrapper into the same folder as MuPlugin.au and rename it “XMyPlugin.au.vst3”, or something like that. This way, on loading, the wrapper would already have access to all necessary parameters and supported bus layouts to report to the host. It would NOT load arbitrary plug-ins after being loaded.

But, regardless, it would be helpful even just to see a tutorial or a description of JUCE’s plug-in hosting facilities. I didn’t see anything about that in the tutorials, Projucer demos, or, e.g., on The Audio Programmer YouTube channel.
Any suggestions are much appreciated!

I think I get it.
AudioPluginInstance, AudioProcessorGraph, and AudioProcessorGraph::AudioGraphIOProcessor all inherit from AudioProcessor; and

AudioPluginInstance::Parameter inherits from AudioProcessorParameter.
So all the member functions a plugin might have to provide to its host can just be relayed directly to any plugins being hosted by that plugin. I don’t know why I expected the interfaces for host and plug-in to be different.
The list of parameters is right there, and they can be copied from the target plug-in as well.

I would still love to see any written info on coding hosts that might be out there.