Here are some tricks that apply to FL Studio & most (but not all) of its plugins knobs & sliders.
-hold CTRL to move the knob more slowly/accurately
-hold SHIFT to bypass the knob's snap points (the points where it makes short pauses)
-Alt+click or middle-click to reset the knob to its default value
-use mouse wheel to increment/decrement the value (in steps)
-use the 2 extra mouse buttons (X1 & X2, when available) to continuously increment or decrement the value
-for "digit" selectors, an up or down arrow appears when you're close to the top or bottom edges, click there to make continuous increments (with a short pause for the first increment). This is actually what the extra mouse buttons are linked to.
for all your functional and musical questions
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