So far I've used Personalised Results / the Globe to raise and lower certain news sites yet when switching to the Video results tab suddenly videos from news sites I've down-voted are prominently visible.
Obviously the goal for me is to curate my news sources a little bit, of course one has to be careful not to enforce too much of a bubble, but the net effect of the current implementation is that arguably the worst aspects of those news sources are still very evident on Kagi.