I asked Ai
The Darts Masters scoreboard may not always display the "finish" (the final dart score to win a leg) because the focus is primarily on displaying the current score and game progress for each player. The "finish" is implicitly understood as the difference between the current score and zero, and it's usually not explicitly shown on the main scoreboard. It's more common to see the finish displayed on a separate area or during the broadcast graphics, or mentioned by commentators.
Wut?