The current thickness is also shown when dragging as well.
The number disappears and is replaced with the original text after 1 second.
Tested and works with a touchpad "mousewheel".
Bug: 372364
Bug Link: https://bugs.kde.org/show_bug.cgi?id=372364
Reddit: https://www.reddit.com/r/kde/comments/65wdow/can_we_get_some_support_for_pixel_perfect_panel/
New Video: https://streamable.com/6w9ry