Is there any hack to change the left click by mouse on Klipper entry in System Tray to show the floating Klipper panel (the one that is shown via Meta+V) instead of the main Klipper window ?
No. But we should just fix that bug. What are you doing to make it happen so often for you? I believe we have a bug report for this somewhere but I don’t recall that it’s a common issue that lots of people are regularly experiencing.
I created many new users, and reset Klipper’s history many times, but the problem always reappears.
I use Klipper as back up with a capacity of 700 entry to save my important links, small sentences, commands, config vars, and small blocks of code.
Furthermore, I heavily use the widget many times per hour, and the first operation I always do when I open it is to search for my saved items instead of scrolling that huge list, but after several searches the result area begins to show overlapping entries that are glued, and you can’t get rid of them even if you clear the search input or even clear the whole history. The only working solution is to disable then re-enable the widget via system tray configuration’s window.
For me Klipper is one of the main core widgets that daily interacts with user, for now I’m using CopyQ as an alternative until the bug is fixed.
NB: This bug was not at all present in Plasma when I started using it 3 years ago.