Zend certified PHP/Magento developer

Issue using Goku + Karabiner elements configuration for caps_lock

I am having an issue with Goku + Karabiner configuration.
Have a setup with the following lines in the karabiner.edn

   {
    :des   "caps_lock to esc when pressed alone, to ctrl as modifier"
    :rules [[:##caps_lock nil nil {:alone :escape :held :left_control}]]
   }

when I press caps_lock real fast, I can get an escape, if I delay it a little bit
I don’t get anything. I increase the variable to_if_held_down_threshold_milliseconds.
Now I can get the “escape” key, but I can’t get the “control” modifier in time. I have to be deliberately slow to get it to work.

My question is why can’t we get “escape” if I tap “caps_lock” alone but if I combine with another key I get “control”. should be simple and straight-forward logic.