Edit 08/22/2022
Added info about the various Layouts that are encoded into an Atmos file.
Some info I didn't add in the main post is that those layouts are a hard embed, meaning you can't get anything higher because it isn't there. The ADM file is NOT able to be retrieved from the EAC3JOC files. Even with the licensed tool from Dolby, you can only get the layouts listed. With the most common tool they provide for this, you can only decode up to 7.1 but this is better because you can use files you've downloaded rather than having to record the playback, meaning Tidal files, since there is no downloader (that I've been informed of) for Atmos from Amazon/Apple