If you've upgraded to SlatablePRO you can now import portrait videos and slates as a Take as well as importing them to the slate gallery in Settings> My Profile> Manage Slates.
To import a video shot in portrait as a Take just import as you normally would in the Take screen.
To import slates to store for later use go to Settings> My Profile> Manage Slates and import there.
With great power comes great responsibility
Unless specifically specified by casting never shoot your audition in portrait mode!
And now a warning...
Video slates imported as Takes will have to be moved to where you want them in the final compiled video (tap-hold to move Takes).
If you're adding slates from the slate gallery you can choose to have them at the beginning and end only of your tape only.
In AuditionDrop if you import a slate as a Take it will be treated as a Take in a Scene. But if you use a slate from the gallery it will be separated out as its own video under the title "Slate".
Make sure you try and test the different ways to use slates in SlatablePRO before an audition.