The above test @ kenrockwell page is made using iTunes via MAC Pro. According to this post, using macOS, AirPlay 2 will always be lossless.
On the other hand, if we are using iOS, iPadOS / tvOS / HomePodOS, AirPlay2 will use lossy compression and 16/44.1 also could be lossy AAC as far as I've read.
I recognize that I'm so confused about this AirPlay 2 thing, that's why I am keep asking to put things together.
In my case for example, Yamaha WXC-50 which is using AirPlay 1, should be lossless 16/44.1 (I am using iOS/iPadOS) but my DAC shows 16/48 not 44.1 and at this point I don't know what to believe, not so sure if it's lossless or lossy.
Interesting and dissapointing if that is the case with IOS.
Using my iPhone 12 with a lightning to USB cable to the front USB port on my A14, I only get 44.1 Khz even with the High-Res setting enabled in Apple Music. I'll have to get a Lightning to USB-B cable to try the USB B input on the A14