@kkga something seems to be missing. You seem to be using another plugin manager, cork (possibly at GitHub - topisani/cork.kak — it doesn’t seem to have been announced over here) but I can’t grep any place where it is actually loaded.
Edit: nevermind, cork is unusual in that it needs cork.sh to be renamed into $PATH as cork, and then it is available as a shell (and %sh) command. There is no kak file defining commands.
Edit 2: I can’t find performance ideas in cork, and I’ve had trouble using it (how to install plugins in the first place?). Each and every cork command spawns bash on top of %sh{}, defines kak commands, and executes them. It is of course possible that you have really fast hardware, so we need to compare comparables. In any case, I can’t reproduce as of now; perhaps there should be another thread for this plugin manager.