Is there a way to export / import an entire DA digest, complete with links into a DT database?
Use Save As to save to the Finder.
Then import the file to DT Pro. If you used Import, you can delete the Finder copy. If you used Index, don’t delete the Finder copy.
The next release will be able to add the Digest via the command Data > Add To DEVONthink > Rich Text. This should simplify such tasks.