Reducing the sugar will be fine. I found my first ones a bit sweet so now I reduce the sugar to about 1/2. Be careful when applying the naan to the tawa. Watch how Chris does it in his video, its easy to miss slightly as I've found out a few times and also with your tawa being non-stick, give it a good slap on and a roll round the edges with the cushion to make sure it sticks for the inversion.