SUMMARY It would be just much better if it could be just like Konsole scroll-back buffer: either freely user selectable or, even better, "Unlimited"
There's a cost to load time, and beyond 2000 entries is just ridiculous.
I think then that the clipboard should get an "on demand" implementation of the history. You load the latest <whatever_makes_sense> history items and only load the remaining ones when wants to browse through them.