Thanks Suhrd for the feedback.

I partly agree that it is not a great idea to provide a complex gesture of two fingers and change direction, but if you read again User is not supposed to aim on any key. User can swipe anywhere on the keypad and the matra will be added to the last typed character.

I will revisit these gestures and would simplify further, the idea is to imitate the writing pattern and match the gesture with the visual symbol of the matra.