Alright, yeah that should be fine. I use to use that method, but found that my roots still went towards the bottom for the most part.
Then I went to the weight method, if it feels really like, it needs watered, then feel it after you water it, see how heavy it see. This method seemed to increase the amount of roots towards the top and middle.
Now I'm using this method and Smart Pots, and my dirt from top to bottom is even roots. Take it in to consideration. No point to change what's working but you can always improve a plant