"WebMonetizationBroadcaster" prefab on to every scene in my game and set there Payment Pointer?
==> I did not notice about this before because I have used only 2 scenes in my game, the Main gameplay and a Leaderboard. I only used above prefab in my Main scene, not in Leaderboard scene. (The extra feature for Coil user is not necessary in my Leaderboard).
When reading your question, I have just tested Coil extension and saw that Coil is still paying during the time I'm watching Leaderboard.
I have used the same Unity Github source as you, so I guess the answer is "No, you don't have to put the Broadcaster and Payment Pointer" in every scene. Hope my answer is not too late for you (Sorry, I was so busy to submit the game on time).
