OK, I got MakePresetFromNamedParams() working with chunks, and updated my git.
There's now a function you can overide to do whatever extra processing you need before the rest of the args are used for the parameters, the default one in IPlugBase looks like this:
Code:
virtual void MakePresetStateFromNamedParams(ByteChunk *pChunk, int nParamsNamed, va_list vp) {
MakePresetParamsFromNamedParams(pChunk, nParamsNamed, vp);
}
There's also an example of using it in IPlug/Example/chunks .