I always need to terminate files in DEVONthink.
There is a good AppleScript template to generate a link to the file and schedule it afterwards, but with this approach I don’t have an overview of free schedule resources in my calendar (BusyCal).
In the past I always copied the link of the file and then switched to my calendar app.
Here an example:
The window of the calendar can be positioned individually on the screen.
If you also use the apps and are interested in the workflow, please feel free to contact me. The required Keyboard Maestro macros are of course available for free.