1) Put Orion in a fullscreen space
2) Add another window or app to that same space (split screen)
3) Shift-Click a link to open the Orion Preview panel
4) Preview panel will be truncated at the split screen point
5) Put the Overflow Menu on the right hand side of the toolbar
6) Click the Overflow Menu
7) If there is another app to the right of Orion, the Overflow menu will be truncated too.
These panels never used to get truncated, they used to display on top of the other app when in split screen if they didn't fit within Orion's portion. This behaviour changed in a fairly recent RC build.
Version 0.99.134.2-rc
Sequoia (15)