After a quick glance in DP10's JS, it seems you can't override the direction in which a popup opens up (i.e. always open upwards regardless of viewport space).
Is this the case in beta 1 with the overhauled positioning system? Will it be possible to override the default directional behavior via a data attribute or something similar?
Pop-up menus have had an overhaul of their positioning system, and will now pop up above their trigger if there is insufficient space to fit in their default position below the trigger.