Iphone XR + Apple TV 3 in 1920x1080?

Hi all,

trying to decide on my Zwift setup to be used with a kickr core…

I would like to get to full HD with minimal expense - I have Iphone XR and an Android phone for the companion app (The Android phone runs Zwift only just ok - not very nice to look at)

I had to find out the hard way that Apple HDMI adapter output only mirrors the screen, which, in conjunction with the Iphone XR leave black bars on an FHD display.

As indicated above, I am wondering whether a used ATV 3 driven by the XR over airplay would be able to provide full HD over HDMI, as I would like to avoid getting an ATV 4K- I have no other use for it except zwifting.

Any input appreciated