Sorry the tooltip font is simply the system font. You can only change the font of the clock. Btw the successor dock (Crystal Dock) is out now.

Thanks a lot. The successor dock (Crystal Dock) is out now and has rounded corners.

Thanks, the successor dock (Crystal Dock) is out now and has rounded corners. It is different from Latte in the sense that it doesn't integrate with the Plasma panel, and focuses on multi-desktop...

Hi, the successor dock (Crystal Dock) will be supported on Wayland.

Still the best and the most beautiful KDE plasma dock!