> the SDK seems way larger than I had imagined, but that is normal for (software) things, I guess. "This API also enables the scheduling of tasks on the main thread from any other thread." was not easy to unpack nor see the use of in what was (to me) an audio-generation-centered API
VST plugins almost all have a GUI, thus the VST SDK has to support an entire cross-platform UI framework... This threading functionality is mostly about shipping input events/rendering updates back and forth to the main (UI) thread
There is no single UI framework in VST. The plugin API only has interfaces for creating/destroying/resizing a GUI window. You are not required to use VSTGUI.
VST plugins almost all have a GUI, thus the VST SDK has to support an entire cross-platform UI framework... This threading functionality is mostly about shipping input events/rendering updates back and forth to the main (UI) thread