Ungovernable
Thanks - first off, let me say I would heartily agree with all the sentiments you express here.
My concern is primarily that I get the impression the people moderating the German-language feed don't actually know its sites well enough to properly moderate the feed. You really need someone who's actually familiar with these sources and speaks the language, and it kinda looks like you don't? The point is, banning major, established counter-info sites is a pretty extreme move in this context, basically one of the most extreme singular moderating decision you can make here as far as I see it, and it doesn't exactly look like the people in the thread above are aware of that. That's the equivalent of banning all Mutu sites or nuking IGD because of 1% of the contributions they allow. I will say, I wouldn't particularly object to it in this case, that's definitely reason enough for a boycott on its own terms - you just need to know what exactly it is you're doing there. (At the same time, I doubt this feed is all that widely used in DACH, so chances are people wouldn't notice or be bothered much, anyway).
As for individual sites, de.indymedia is maybe a bit rickety but still in vigorous use and also moderated, as are the other five sites. It's just that basic anti-D stuff is generally considered in-group and not beyond the pale, so they will just carry stuff like what's linked in this thread without much discussion. Knack.news is the worst offender, since it's Leipzig, which is anti-D heartland. Kontrapolis, believe it or not, is already significantly better, since it's Berlin, which is much more international. Tumulte isn't as active, but there will be at least some. Barrikade is the best of the bunch, since it's Swiss, not German/Austrian, there's barely any with only few exceptions. Emrawi is worse than Kontrapolis, but maybe not as bad as Knack. Indymedia will cross-post a chunk of these as well. So even without adding the three local German sites, there will already/still be a whole bunch of further articles like that on the feed right now, if you go dig for them, both since last autumn and from before that, too. And plenty other sites on the sources list might have published stuff like that too, of course, there will be at least a few instances. If you want to be absolutely certain to not spread pro-Israel/Zionist content, you would basically have to shut down the entire feed. There's simply no straightforward way of cleaving off this stuff without removing large chunks of sources and throwing out lots of unobjectionable content in the process. So in that context, singling out a site like Kontrapolis isn't really all that meaningful.