Trouble with Vector3.Angle() and RotateAround()

Hello everyone, I'm scripting a "turret" that looks at a target position (ignoring the Y difference between the two if any).

Unfortunately I've become stuck on a problem where I can never (on purpose) get Vector3.Angle() to be 0. At this point, the value will become close to 0 (say 0.03) then start flipping back and forth between the positive and negative value of that small number) which you can see in the screenshot. Occasionally, the value does become 0, but I don't know why.

I thought that the way I have the relevant part of this script would handle this (in that the desired rotation amount, at a small value, becomes the remainder of the current rotation to 0, meaning the angle should be 0 on the next frame), but obviously it does not.

                 //check if the Turret has a clear los according to whatever its impassible layers are:
                 Debug.DrawLine(transform.position, currentTargetPosition, Color.red);
                 if(!Physics.Linecast(transform.position, currentTargetPosition, impassibleLayer) ) //if raycast dosen't hit anything...
                 {
                     if(turretCentered) //update Turret so it knows it is not centered anymore
                     {
                         turretCentered = false;
                     }
                     
                     //Turret does not care about any Y position differences...
                     Vector3 currCustom = currentTargetPosition;
                     currCustom.y = transform.position.y; //ignore Y differences...
                     
                     Vector3 directionVector = currCustom - transform.position;
                     
                     float angle = Vector3.Angle(transform.forward, directionVector);
                     Debug.Log("angle is: " + angle);
                     
                     float rotAmount = maxRotationSpeed * Time.deltaTime;
                     Debug.Log("initial rotAmount is: " + rotAmount);
                     
                     if(Mathf.Abs(angle) - Mathf.Abs(rotAmount) <= 0f) //don't overshoot desired angle (which is 0)...
                     {
                         //Debug.Log("RotateTurret() breaking...");
                         //Debug.Break();
                         
                         rotAmount = angle; //set rotation amount to the remaining angle...
                         Debug.Log("rotAmount = angle: " + rotAmount);
                     }
                     
                     //now figure out if turret should rotate to the left or right:
                     if(Vector3.Cross(transform.forward, directionVector).y < 0f)
                     {
                         //Debug.Log("cross.y is <= 0f");
                         rotAmount = -rotAmount;
                     }
                     else
                     {
                         //Debug.Log("cross.y is > 0f");
                     }
                     
                     Debug.Log("final rotAmount is: " + rotAmount);
                     transform.RotateAround(transform.position, transform.up, rotAmount);
                     //

Any ideas on what is happening is appreciated, thank you for reading.