I may be not have understood your requests but it is possible to use the mouse scroll button upon the slide bar to increase / decrease the exposition or another parameter.
And also with the arrows up & down or left & right.
That is correct, but you need to select the adjustment bar and keep the mouse pointer there to use the scroll wheel or the directional keys, and the scroll wheel adjusts setting values by fives so it can’t be used to set a specific value,
Hopefully this has to be done, otherwise if we simply need to be over the bar to use the scroll wheel, it will end by having often unwanted correction simply by scrolling in palettes.
I’ve already had this method in other tool and it is particularly tedious.
So yes, the slide bar should be clearly selected before accepting any move from the scroll wheel.
Well, I come from Bibble software (AfterShto Pro nowadays), which have a more “mouse over” (and shortcuts) oriented UI and I feel that it’s easier and faster to use the sliders & fields without having to first click on it to select them.