Consider using the KDE keyboard shortcut tools to set up a permanent paste keybind instead of using the history.

For example, I have a keybind that sends a known mouse movement input, which I use to set that known mouse input to always correspond to ten centimeters of on-screen movement.

Using a keybind would remove the need to ever select the right item from the history, and reduce the clutter in it for copy-pasting other things.