Can kids under 15 stay in Thailand on a tourist visa indefinitely without fines for overstaying?

I always extend and follow the same rules for my son as I do for me. I just think it is respectful to do so but also I worry about any future implications not following rules could carry as I like to come to Thailand often so I'd prefer to do things right despite him not necessarily needing it. Everyone says it depends on the immigration officer on the day when you do different things and last thing I'd want is questions galore around this or it to even impact my son or me returning or it affecting my ability to get a longer term visa at a future date.