The second bit simply says "third party service" - nothing stops you from doing the combined chat overlay locally and streaming the result.
Also, twitch is still very much the top dog, but you're right - they're actually having to compete against youtube now.
The spirit of the terms seems to be they don't want combined chat, and are relying on the fact that most streamers are not going to develop their own chat combining software.
If people try to get past this on a technicality, expect them to revise the conditions.
Why are you commenting on something you clearly know nothing about?
For the rest of us who also know nothing, could you expand on your thoughts? Information is much more interesting than an internet slap fight :)
But, silly pedantry aside, my point still stands. It seems like Twitch doesn't want chats combined, regardless of the mechanism.
A huge majority of streamers rely on overlays provided by either the companies Streamlabs or StreamElements for things like displaying a chat on their stream, among others.
If, as a user, I think the video quality on another platform is superior to that on Twitch and knew that there was an alternative platform where I could watch the same thing at higher quality, the experience on Twitch is clearly less than that on the other platform. This breaches the first guideline.
> The second bit simply says "third party service"
And this is the real point: it simply says. It doesn't clearly specify, there is no definition of these terms. These vaguely/innocently worded hints will be enforced opaquely whenever they feel like it, without explanation of what, specifically, you did wrong.
I think that is either legalese or poor wording in the text of the actual guideline, The FAQ has this to say about personal use of chat combining software:
> The prohibition on third party tools only applies to content presented to viewers either on or off Twitch.
"tools" and "applies to content presented to viewers" I think gives an idea of how they will actually enforce this versus the "service" wording of the guideline