Possibility to hover the mouse above any parameter and then use the mouse wheel to change that parameter. Pressing i.e. Shift would allow for finer control. This mouse wheel behavior could be optionally remapped to a knob or a fader.
Users could enable and disable this behavior in their settings. Testing should be done to avoid collision with mouse wheel scrolling (see how Cakewalk addressed this problem).
On a hardware mouse you have to click a parameter and then move the mouse. Changing parameters with precision involves several muscles and some skill. In comparison, the mouse wheel doesn’t require to reposition the mouse, and precision can be achieve moving just one finger. The optional use of one knob or one fader offers simiilar advantages.
It’s a workflow improvement.
The official click and drag behavior. Or mapping every parameter to controllers.
Only within the VST UI, if they bring this feature.
Among DAWs, Cubase, Studio One, Cakewalk.