What is HDMI Audio Output "Expert Mode" exactly?

[SkyhawkDriver]

Have an XG1v4 connected to an AVR via HDMI.  In Device Settings > Audio > HDMI Audio Output there are 3 choices, Stereo, Auto Detect, and Expert Mode. 

Can someone please explain what Expert Mode is specifically?  It doesn't appear to do anything different to Auto Detect, passing DD 5.1.   What exactly should I see that's different?

[RobertWy]

From google:

"Search Results

Featured snippet from the web

Enabling Dolby ATMOS on X1

Once you have connected your Dolby ATMOS compatible stereo system to your X1 TV Box via an HDMI cable, visit Settings > Device Settings > Audio > HDMI Audio Output and select Expert Mode."

[SkyhawkDriver]

I had already found that post in a search. Expert Mode doesn’t appear to enable Atmos. My AVR supports Atmos and using bitstream via eARC, I can decode Atmos from the Netflix app on my TV. On the Netflix app on the X1 DVR, just DD 5.1.

I was hoping for more detailed technical info, not a high level forum post.

[SkyhawkDriver]

Anyone? Any Comcast employees who know or can escalate and find out?

[Fancher1011]

expert mode will allow you to get a dolby digital + signal to you avr  and auto will only do standerd dolby digital but expert on certain boxs is supposed to give atmos too im trying to find what box for sure it takes i want one.