Please note you do need Surreal Sound pro package to really get the Dolby atmos max experience. I have it on my Gravity and I just love it. A lot better experience compared to Tesla.
No. It most unfortunately does not. The only true source to get Dolby Atmos in Gravity is thru the native Tidal app. You can turn the settings on in Apple Music, but it will not come across in Dolby Atmos.
Yes. I cannot speak for ios27 as I am not on the beta for it. I would say unless Apple made a change, it's just the quality of the Gravity system and the updates in software Lucid is pushing out is the difference. They did mention improvements to sound in 3.6.3 I believe.
I have to be honest, I've been on the 27 beta since the first release and didn't try it. I know it definitely did not work in iOS26, playing the multichannel test tracks only worked in stereo.
You can search Apple Music for Atmos test tracks and play them to see if it's working. I'll test it when I get my Gravity back from service today or tomorrow.