I'm not a fan of shadowbanning the 'extreme' solutions from the tradeoffs view. I spent quite a while trying to figure what the 875 cycles solution could have possibly been in D7, before I finally realised that because its not on the cost tradeoff list (which by the way is quite hard to find, only showing from hovering over some parts of the dotted lines, I think it would be much better if it was just a static part of the stats page), and therefore is probably one of those solutions you deemed 'extreme' and filtered out. And the fact that this happened to me even helped me figure this out, if I wasn't already aware of this I wouldn't be any wiser seeing the 875 solution in the cycles graph :P Maybe I would have never figured it out.
I also don't think removing them outright would be a nice solution, they definitely deserve some recognition :P
Also, having one set treshold where you just start shadowbanning them does have its own set of problems, such as deciding the exact treshold, for example levels E7 (I had a nice back and forth with someone but I couldnt see their cost yet and also couldnt communicate with them, ties into my other questions :P) and G4(not exactly sure if this qualifies as extreme or whats going on here) currently have such extreme solutions that kind of ruin the treshold graph.
Overall, I am still in favor of having a logarithmic cost graph rather :P It makes the most sense IMO, especially with how much the cost grows as you add conditions. I think a log(cost)-cycles or a log(cost)-log(cycles) might even be a nice fit for the game, similar to viewing a 2-parameter front for a genetic design algorithm.
Lastly, I've already mentioned this a couple times but I do have to agree with domnomnom, a community where people can chat with eachother about the game would be very nice :P You mention the possibility of a forum but live chatroom(s) where you can go back and forth quickly is more appealing (to me at least), hence the reason I proposed creating a discord server earlier :P