[chuck-users] --callback&--blocking (RTAudio?)

Fellow ChucKists, Dear Gary, I'm currently working on extending the manual section on the comandline flags for starting the VM and ran into --callback and --blocking. While mentioned in the online docs (which I'm basing my text on with some additional notes) these flags aren't explained in any depth beyond them being related to buffering. I suspect they relate to the interaction between RTAudio and the host-system/ soundcard but the way in which they do so isn't at all clear. Is there a place where more info could be found? Yours, Kas.