okay last one for a while i promise...sort of a pitch for using the AudioSDK in Unity.
it occurred to me that as i mentioned using the Unity AudioSDK instead of your current system around AudioSources, i did not think about how useful using a Mixer plugin is to, well, mixing. assuming that CsoundUnity can support loading multiple CSD files, it means routing between effects and instruments could be set up visually, like a bus send for individual synths, and all of this can be utilized in Snapshots or exposed in the Editor. currently individual synths could be routed via their respective Audio Sources to Output Groups, but any effects that one wanted to apply globally might be a tricky thing to manage with the send volumes set in the CSD file for each instrument and the effect output as an Audio Source for the effect's CSD. i can see the synths using AudioSources, but effects would greatly benefit from being a Unity mixer plug-in, or located there.
continuing on that front is there a good example of mixing in Csound, and especially of things like a bus send or something like this? in terms of the 3D sequencer i was definitely thinking of being able to say, turn on an effect for one particular event on one layer, but make a send available to all layers that could be turned on if desired. i didn't see any mixing examples per se but of course there's all that additive stuff where you're obviously mixing many waveforms or partials into one output. but aux sends is what i'm thinking of especially.