The recent games section should be responding to whatever key or button is bound to the "Switch Image Type" shortcut key in Big Box. Each platform remembers its own image type, and yes, currently that image type is the same across LaunchBox and Big Box. I'm not fully following what isn't working correctly there. Are you trying to override this in the XAML?
I'm not aware of a way to make the images centered, but there is probably a way to do it. I'll admit that the Recent and Favorites sections were never fleshed out very much because they weren't commonly used by themes. I can look into fleshing them out more though, but it might be a bit yet.