You should be using the nuts that hold the cable to the bracket to adjust it instead of the screw at the end of the cable, that thing is getting destroyed (I made the same mistake a few times before figuring it out lol). I have the Lokar throttle and kickdown cable setup on my Duster and adjusting the kickdown is tricky, it's a pretty narrow window to get it just right. I'll adjust the nuts by only about one turn at a time. Loosen the nuts and thread the cable sheath back so it's roughly half way instead of all the way forward like you have it now.
Overall though I don't think that extension piece on the carb throttle linkage is going to work right with your KD cable, I bought one of those and put it on an Edelbrock I'm swapping into my truck and the instructions show that bottom hole with a small through-bolt to hold it to the throttle bracket along with the top one like you have. I believe that bracket is only intended for using the factory throttle cable AND kickdown rod connected to the factory pin/shaft thingy. The locations of where the cable ends attach to the throttle bracket affect the travel ratio a lot more than having the cables slightly angled instead of perfectly parallel (one may be slightly farther from the pivot point of the throttle shaft than the other).