Watch out mate, I had a moderator suspend me for making a similar post (after accusing myself of telling lies about this problem, and then lying himself, before deleting the offending posts. It was quite hypocritical to say the least). These are the "support" forums for Roxio products (according to several links on their website), however according to the mods it is a users forum. That means most of the mods have never used this card before, but have used many other Roxio products over the years, and right now are caught between a rock and a hard place with all our complaints since we have been directed here.
I went via the support route with a spare CD key I had, and they said to use OBS, which is a true croc of **** for the same reasons you stated, plus using OBS does not work with all graphics cards (some just show a blank screen or a test pattern of colour bars).
However after continual posts on their Facebook page and Twitter they have finally acknowledged the problem. They have said they are liaising with Twitch, however I have tweeted Twitch Support to see if that is actually the case. Either way, this seems to be getting resolved finally (after a little persistent posting by myself on their social media accounts), but at the same time I would advise you to get in touch with them via social media and keep up the pressure, as until there is confirmation that a patch has been made or that they have contacted Twitch then they could just be saying that to fob us off, after all it took multiple messages and posts from myself for them to stop ignoring the problem.