I do know one, but I won’t plug it. I want to keep this article and its discussions clear from self-interest. But I can demonstrate it:

Untitled-1

This is scaled down, just for the sake of a demo. Top half is a 200MP photo, over 30,000 pixels wide. It’s the overview of a scene that has hundreds of animals hiding in it if you zoom in, quite fun.

Bottom half is zoomed/panned on the elephants drinking by the river, on the far right of the scene.

This is 7 years ago, on the web. Without breaking a sweat. There’s zero reasons to constrain resolution if you’re storing the original anyway.

In any case, an improvement is an improvement. 6K is a start :)