I just blocked YouTube chat entirely because it pops open whenever you full screen a vod and that's hella annoying. It also has some sort of memory leak which leads to tabs crashing and that's been an issue for at least a year now. I think it's proof that the people working on YouTube features don't actually use those features.
@GapYoukai I haven't experienced that personally, but it's probably in the way that I use it. I don't usually have big queues or anything, most often I open videos in new tabs.