Preface: I will refer to no ADS, no point shooting as neutral stance.
CQC-Control-Scheme (FPP):
L2 (toggle): point shooting
L2 (hold): full ADS
Make it that when you are in point-shooting-mode and then hold L2 to go into full ADS and then let go of L2, it returns to point-shooting-mode. When you go full ADS by holding L2 from neutral stance and then let go of L2, have it return to neutral stance.
In addition to toggling point-shooting-mode via L2, make it that the player cancels out of that mode when pressing L3 so that the player can move backwards, sideways or sprint away immediately. That way players are not trapped in that point-shooting-mode when they want to do an evasive maneuver. When moving forward and cancelling point-shooting-mode via L3, sprinting should happen immediately. This allows for reactive gameplay.
L3, R3 (toggle) whilst in ADS: lean left and right
Make it that when you are leaning right and then press L3, the character makes the full motion to leaning left. Same from leaning left towards leaning right via R3. This allows players to peak slim objects such as trees and pillars effectively from both sides.
Remove ability to lean in point-shooting-mode to enable cancellation of point-shooting-mode via L3 mentioned above.
R1 (toggle) whilst ADS: hold breath
CQC-Control-Scheme (TPP):
L2 (hold): point shooting
Letting go of L2 whilst in point-shooting-mode lets the player return to neutral stance.
L2 (toggle): ADS
Toggling Switches between ADS and neutral stance.
R1 (toggle) whilst ADS: hold breath
L3, R3 (toggle) whilst in point-shooting-mode or full ADS: lean left and right
Love your game, hope for many years to come!