Yes reload component should not be necessary, restartComponent (Steinberg::Vst::kParamTitlesChanged | Steinberg::Vst::kParamValuesChanged) already implies that the plugin will be deactivated and re-activated right?
Then the plugin should load the new preset and expose the new parameters after setActive(false). Is that correct?
I think it is pretty much obvious because if the new preset implies loading files from disk, allocating memory, initializing and computing structures etc… this can’t happen while the plugin is processing.