Until the Zap.stream menu issue gets addressed, the multistream (on everything, so Vaughn debut is a-go) will be done via Sorayuki's OBS plugin; ideally there shouldn't be any weird stream fuckery since I'm streaming to Vaughn natively and then using the plugin to restream to both Zap and Robotstreamer, but I can't say for sure until tomorrow morning.
Hopefully the site-side issues are addressed soon.
Now I wonder if anyone besides Verita (when he was here) had the same issue?