[NTG-context] How to center floats (?) in standardmakeup?

Hello everyone, I am trying to create a title page with \startstandardmakeup[align=middle] This works alright for text, but when I am trying to insert a "\framed", a table or an "\externalfigure", those items (floats?) don't get centered. How can I make them centered as well? Thank you very much for your time and kind regards, Thomas