About the crowns, there's a sweet spot on all bikes..not all crowns have to be the highest as they can be. We all know or forget that the BB does rise up and handling can feel sluggish and weird. Seems like everyone just slides them up as high as they can go since "everyone" else does it... Frames like these already have slack HA and don't need any extra.
Actually there is no sweet spot because biking is all about personal preference and different riding styles. I tried it raise and it was much better. Maybe the bike isn't slack enough?