So, the work with developing our own multi-platform mixer (rather than using all the various platform APIs) will really enable us to do exciting things like allowing users to write their own per-voice and submix effects.
Once you have this ability, wrapping VST plugins (or any plugin) should be pretty straightforward – it’d be essentially just writing the glue code between the audio effect plugin (which is simply a dll) and the UE4 effect interface. So yes, eventually that sort of thing is something I want to support.
Imagine the workflow where from a UE4 project, when you got to create a C++ class, you’ll be able to choose from an IAudioEffect base class which will create a subclass that implements the interface to define an audio effect. Then, automatically, this user-created audio effect would show up in the UI as an option for adding effects to sound cues or a (new) submix-graph editor. That’s the sort of long-term vision of where I want to take UE4 audio. I’m only now being able to get back to focusing on making progress in that direction after my recent work to help ship Paragon (and Fortnite) so I’m a bit hesitant to make any promises in terms of timelines.