Not sure if this is the right place, since it’s little bit off topic, but.
If you place any script in /Users/YourName/Library/Application Scripts/com.devon-technologies.think3/Menu/Bookends/NameOfAnyYourScript you will get the new menu: (Script Icon) / Bookends / NameOfAnyYourScript which will run this script 
Well, they are two different scripts, I’d say two different approaches. Hence, there are no good or bad script, this is the matter of how well this script supports you workflow:
Export to Bookends script:
- takes the Record you selected in DT
- reads all meta data (authors and keywords), if they are present
- reads the bunch of custom meta data (6 of them, like DOI, publisher etc). This means that you previously endered it somehow before running this script
- copies the PDF in the folder of you Bookends attachments leaving it indexed in DT (means deconsolidating in DT AppleScript)
- and finally makes the ref with these properties and attachment
This workflow means you have a PDF in DT, which has all the necessary information (metadata, and custom metadata), that you found somewhere and entered manually or automatically (if possible). If all this is set up - you just run the script and it generates the appropriate Ref in Bookends with all these properties and moves there the attachment, leaving it indexed in DT. There are no connection between these items, and if you change later anything in BE, it will not sync with DT (except what goes with the file). Other cons follow from the fact that this is the indexed file.
My script
- Takes the record you selected in DT and the Ref you want to connect with it
- Connects them for further sync and jumps (writes PDF DT UUID to user field of BE Ref, and Ref ID to custom metadata of PDF)
- Takes all needed data from the Ref (url, notes etc)
- Formats the PDF in DT (writes url, notes) renames PDF with the correct chosen format - ‘Author (year) Title’, and writes EXIF data to PDF (author, keywords, title etc), data needed for sync
- Attaches PDF as attachment to selected Ref
This workflow means, that you find any PDF containing the publication you need, wherever you find it (be sure to OCR if needed before you run the script, cause OCR changes the UUID). Then you use Bookends to find a ref file (with Bookends powerful search e.g.), I use Google Scholar. You just create a Ref (or import it from internet) and you have all the data you need (Ref with Authors, Title, Publisher, Abstract, DOI, ISBN, Pages and many more). Then you just run the script and get attachment to the Ref, and all correct metadata to you PDF in DT. When you change something in BE or DT with time, you can easily sync all changes, just runing this script again. But I use a smart rule which is run periodically and see if something is changed. If changed it syncs these changes.