Option 3: Streaming platforms add to their contracts with ad delivery networks that they must faithfully represent a ReplayGain value in the metadata of every a

Option 3: Streaming platforms add to their contracts with ad delivery networks that they must faithfully represent a ReplayGain value in the metadata of every advert before delivery. The streaming platform can then have its clients adjust the volume they play adverts at. Bonus: the clients can sample the advert audio and send back the computed ReplayGain, compared to the claimed ReplayGain. Add a penalty clause in the contract for every single advert delivered louder than claimed.