I’ve only just noticed a Finder folder in my Home folder, apparently placed there by DT in September of last year. 
Is there anything special about the DT folder, or is it just there as a convenience?
Hitherto I’ve been keeping my DT databases in a folder named LOCAL in my Home folder because I didn’t want those huge files taking up iCloud storage.
What is the name of this mysterious folder?
Apologies for the mystery. The folder is “Databases” with a DT logo on it.
To my experience that folder gets created automatically when you install (and launch) DEVONthink 3.
Ever since starting with DEVONthink 1, I always had my databases placed in folders that I created at locations where they fit for me. When I recently installed DEVONthink 3, I recognized that folder you mentioned in my home directory, but it was empty. So I assume you made your installation in september last year and that’s when this folder was created.
Yes, the Databases folder is created when DEVONthink first launches. It is a convenience location for people who don’t know where to store their databases, or a place to relocate them when needed.
Excellent. Thank you all for your quick replies. I can now proceed in comfort! 
Although one needs an ants-eye view to make out that logo. Easy to miss 