I have created a Butler automation to move completed cards from one Trello board to another. Will that mess up my stats?
If a card is moved from board A to board B, you will lose the card history from the board A since the Trello API won't return it anymore. Instead of moving to another board, you can create an automation to archive the card.
Once archived, the card is no longer visible on the board but is still included in Trello's search feature, and can be returned to the board at any time if needed.
Another option is to add a delay of at least two hours before moving an item. That leaves enough time for Screenful to register that the card was completed (sync runs once per hour).