We've just released a small update (version 1.0a) - as we'd noticed that certain visual effects took a strain on the processing power and dropped frame-rates during streaming / live recording. These small fixes should be unnoticeable to most but should help with optimising live-streaming!
Incidentally, if you do stream 999 on Twitch, be sure to let people know as 999 is set up as a recognised game on Twitch!
https://www.twitch.tv/directory/game/999