JHBD001,

Thanks for your comments and questions. Here are the answers:
(1) Are both HDMI outputs simultaneous and compatible with v1.4 at least - with v2.0a on #1?

Yes. Both outputs, available simultaneously on the 976, are compatible with v1.4, for the output #2, and v2.0a for the output #1, which is backwards compatible with v1.4.

(2)Will HDMI out #1 be upgradable (e.g., firmware)?

No. Output #2 will not be upgradable; it will remain available for any v1.4 use.

(3) XLR audio outs are from balanced op-amps/driver and not transformers?

Yes. The XLR outputs are balanced outputs from low noise op-amps with a common mode rejection ratio of 100dB, typical.

(4)Will 976 fold Dolby Atmos UHD Blu-Ray audio to 7.1 (7.2) correctly? (It seems to always go to 5.1 on the 975. Is this correct? Depends on the disc directives? I missed the memo with the answers?)

Yes. The 976 will properly decode the core 7.1 channels of the Dolby Atmos tracks as Dolby Digital True HD.
The 975 is also capable of decoding the core 7.1 channels of Dolby Atmos tracks.
Ensure that your 975 is set for a 7.1 system in the speaker configuration menu.

(5) Tested with any 4K capable Blu-Ray players yet?

Yes. The 976 has been tested with both, the Samsung UBD-K8500, and the OPPO UDP-203
As you may be aware, both players incorporate two HDMI outs, and if you are presently a 975 owner, one output goes to the 4K display and the other output sends audio only (with a blank picture) to a non-4K processor or receiver.

However, the OPPO UDP-203 offers a tempting and clever “extra”. It ALSO has an HDMI input. This means that besides playing any type of Blu-Ray( both regular and 4K), you can hook up another 4K source, (such as the latest Roku), and run the audio to our 975 and the 4K picture to the display!

Peter