Quick Swap

Pressing/releasing crouch cancels weapon lowering animation.

If you are on MKB, binding crouch to SCROLLWHEELDOWN(as a secondary key) in the game: The advantage SCROLLWHEELDOWN has is you crouch for less time, but in exchange, you're unable to trigger Quick Swap via uncrouching.

(Note, this isn't a macro since you bind SCROLLWHEELDOWN in-game, not via external software).

Make sure to scroll the wheel ONLY after you use the ability (e.g., press shield → SCROLLWHEELDOWN, not the other way around).

Note: Quick Swap does not apply to lowering abilities, only primary weapons.