Not sure if that’s the question you’re asking but, the Atmos mixes are a completely separate deliverable. They need to be the same length as the original stereo

Not sure if that’s the question you’re asking but, the Atmos mixes are a completely separate deliverable. They need to be the same length as the original stereo master and obviously shouldn’t deviate so much that they sound like a different piece of music, but there’s a lot of scope. Also, the loudness wars are kind of over now that streaming platforms normalize to a loudness target; if your track is super hot it’s just going to get turned down.