Saw some useful clarification in the #pattern-lab channel on the Drupaltwig slack about which version and edition of Pattern Lab is recommended to use with Drupal going forward.

• As far as which repository to use, EvanLovely and Salem Ghoweri clarified that we should be using the main Pattern Lab repository, not the Drupal fork that was previously active. Most if not all of the changes from the fork have been merged back into the main Pattern Lab repository.
• And regarding the edition, EvanLovely somewhat surprisingly recommends the Twig edition over the Drupal edition. Apparently the differences are minimal, and "A true Drupal edition is better represented as a Drupal theme with the Twig edition integrated."

So in summary, the next time you need Pattern Lab for a Drupal project, go here.

Helpful clarification given all of the Pattern Lab forks and editions floating around out there.