Good to see your improvement in focus. I think it would come if you chanted Jam Butties or your own name to be honest as the words serve as a focus point.
However it would be interesting if you could measure your energetic field whilst doing the mantras to get a solid sense of what the sound and visual intent are creating in your fields plus your physiological response.
Not sure if there is kit out there which has been revealed to the public that would measure that response although I guess the military or black ops have the instruments.
But in the meantime keep focusing as it will help with manifestation now and in the future.