Just curious. Are you using some kind of precise measurement for the ammonia dosing?
It doesn't have to be accurate. Anywhere between 2~6ppm should be fine. Below 2ppm might risk the "food" is run out early for bacteria before the next dose, above 6ppm might risk the bacteria themselves being poisoned by too high too toxic level of ammonia.
It also seems when you increase the ammonia concentration to 4ppm, you get 1ppm in the morning. I would suggest to increase the concentration to at least 5ppm at night. So the bacteria will not run out of food before you dose again at night. This can cut down the fishless cycling time. Yes, to speed up the cycle there are just too many factors. This is just one of the many you can do to make it slightly faster.
Don't forget to check nitrate and PH to determine if you need more partial water change to restore the water buffer.