Private areas dont sound actually a bad idea.
I feel your comment like your not really taking care about this, actually KS is a good reason to stop playing and i'm not the only one who think exactly the same.
I think you should add more areas , the one you mentioned requires items or special access for and if it's so Good as you describe so then why those high levels (300+ levels) are still messing with areas 150 and 200. Didn't you create enough areas for levels 300 to 400?
I know everyone here deserve a value, but if i were you i would take more relevance of levels 150-250 which represent the majority-
or a good thing you can do, stop adding shinies respawns in those areas that are suppused to be for massive hunts -