This would definitely increase engagement, and get the community more thankful toward the person who paid the 200k sparks as it would benefit everyone - even if by a small amount.
Games like - Shellshock for example - or card games etc - do not need 2-4 videos of the exact same screen during Co-stream. I see having a 'Costream Chat Only' option as being an amazingly useful option.
Something as simple as @Mods in chat - the line would only show up to the moderators and the person who typed @Mods .. This way, Mods can communicate with eachother privately. This 'channel within a channel' could also throw up status messages (User @XxBigJerkxX was timed out for 5m by @ModeratorName. @SeriousSpammer was banned by @ModeratorName).
There are some exciting opportunities to leverage Xbox Live’s persisted chat infrastructure to help us build out an awesome Beam messaging/whispering/alerting system, and we’re evaluating the best “Beam friendly” way to present this now. No ETA on a release, but would love feedback on this feature.
I wish Whispers showed up both in chat as they do now, AND went to a separate tab in case you missed them. Similar to how WoW would do back in the day (when I played)