An excellent summary which exceeds my understanding of HDMI protocols. After much deliberation over months I shall now invest in an Apple TV box to extract HiRes audio from Apps.

Also my dealer suggested there was little advantage for me to migrate to v2 UHD722 as my TV doesn't do HDR10+ but can do DV and DV from disc and Apps seemed ok but it does sometimes give issues.
You say you used Input 8 on the original UHD722 but there are only 7 - did you mean input 7 (marked "Disc")? I'm thinking now to upgrade as at some point I will upgrade my TV and will need HDR10+ and reliable pass through of DV.

Regards
Bob

861v8, UHD722v2, 5200s, 5200HCSEup, M6s, 3200s, DSW, Sony 55A95L, Oppo 203, Sky Q Silver
Samsung QE43Q65B, Oppo 105 & Sky Q Mini