In my opinion, there are only 2 options that will work.

Either u18 remains with Youth set up as it is now.

Or

u18 decouples from Youth and is based on NPL and League 1 comps and is part of seniors again. This means Mid Coast and North Coast don't field teams in u18 which means they need to look for senior clubs in their region. Probably not a bad thing as it may allow for some focus on improvement in senior comps up north or teams from up north join NPL or League 1.