Just report that TV os 15.3 Beta 3 still shows stuttering while playing Netflix dolby atmos content.
It is less than on 15.2 public. Also shorter period of stuttering but, it is not fully fixed.
I do not have access to the assistant app so hence reporting here.
I have the ATV 2021 connected to a Denon x4700h using a Belkin 48Gbps HDMI ultra cable (certified for ATV)