Due to most people's lack of knowledge on how a mod works and think it's terrible just because it's not entirely easy to be good at. That doesn't mean it should be excluded from an event such as clan league due to an opinion like such.

Tk while taking a lot of time to understand properly and learning all the small mechanics behind it, is a very fun and competitive mod amongst those who do play it often and are good at it.

I'm not going to say anything about boxshu due to its in the same spot as any form of tk mod. The only reason I could see them excluding it is due to the box itself being glitchy and can commonly kick a foot through/into it and being stuck or if you touch the very corner on the bottom, you dq. The only other reasoning I could see would be it being partial insta gib.

I do not know for sure but this is the only reasoning behind why I personally don't think it's in cl. I wouldn't mind seeing it on that list myself either though.

Not to mention, there is already wushu3box.tbm in the mod list. Which is basically the same thing without the instagib.