Currently sliders in Picard just move one step into the according direction when clicked somewhere. This is the default Qt behavior for Qt on systems other than macOS. This affects the sliders for preferred releases and volume and speed control of the player.
But the typical behavior of sliders on all systems I have tested (macOS, Windows 10, Linux GNOME, Linux KDE Plasma) is to directly jump at the position the user clicked on. I think this is also expected user behavior.
I propose to change the sliders in Picard to behave like this. We already have an implementation for this behavior for the progress indicator of the player toolbar and it is trivial to apply this to other sliders as well.