Hiding an entire channel should at least work, that much I was able to directly confirm.

Although it was not without a twist. Originally, I blocked asmongold and his shorts channel - so far so good. But then he made a second shorts channel. Okay, blocked that too. But then unrelated third parties made another "fan" shorts channel, so I had to block that too. I'm not sure how many further iterations there will be, but most of the time and for the most part, I did manage to get rid of him from my feeds, so that's something.