Hello, totally new here and very recent Roon user.
I found this topic and liked a lot the idea of have a display when using the Radio Mode. So I bought a Nest 2nd generation second hand for 35€.
I used the accessibility set up indicated by @TTGolf and works perfect with this 2nd gen. Even, as you can see in the picture, no red or orange line around the picture. Yes, initially it appears when starting the Window mode but you only need to tap once with your finger to have it out.
As a newbie with Roon I found that some info was missing here about how to have the display working, the Roon setup, so for other newbies to come here is that extra info.
First, you need to have the Nest activated as Display and as Audio, both, to have it working.
With Nest active in both places you must select your audio system output and press the volume icon. Then select the display icon and finally press the Activate option at the right of the display icon.
I was worried after read some user problems here but it worked like a charm and I love it.
Is important to have the bright of the screen near to maximum to have the best watching and reading experience. That was my only interaction with Google “put the bright to maximum level” (I did it in Spanish really). Then I closed the mic and with that ended my interaction with the Nest because for me is only a display for Roon.
Hope this will help the newcomers. And thank you very much for this thread and all your post.