This is really great. I think he should be able to win this Junior Title, which would put him at Number 3 in the junior rankings. Also the points from Wimbledon qualifying will bump him up to around 669 in the Mens Rankings. I don't expect he'll be playing any more junior events besides the Junior US Open, as winning that gets him a qualifying wildcard. His current ranking should get him into any futures event, so his junior ranking doesn't really matter.
I believe Kubler was the highest ranked played in the tournament in the men's rankings. Luke Saville has only won one senior match against a player with a ranking. Broady is definitely the favourite for the final, though that doesn't guarantee anything. But then it is hard to be confident that it would be beneficial for him to win, given the heightened media expectations that would result. His results against the seniors this year are the best aspect of his progress.