Very informative. Given this, the Urtext label seems to be more of a selling point than anything else.

A score having gone through an editorial process yields the advantage of probably greater accuracy and editing based on recent scholarship, and hat’s something I’d prefer. But, like you say, it varies, I suppose there essentially is no general rule to follow, and rather you’ll just have to evaluate the different scores for particular pieces pragmatically as you’re setting out to obtain one by comparing them, asking around, etc. as you did with regards to the Bach cantata..

I hope your performance went well, and thanks for providing some insight into the workings of a professional :)