letting him play for 20 mins per game is going to hurt his development, unless you want him playing both NSW Cup and FG. IMO the correct choice has been made. Letting him play in NSW Cup will aid him in his plight to get a FG position next year. He has improved since the beginning of the year, however he needs to keep working at it.
If he is making crucial errors in NSW Cup, he will make even more crucial errors in first grade. It all part of the learning curve. Moore has made the right call not to put him in the team.