I've got a 2012 Macbook Retina talking to a Samsung 4k TV.
I'd actually like to revert back to 1080p.
All the google searches I try talk about going to 4k, but I actually want to go the other way, back down to 1080p.
Although I do get the font-size option to make the fonts larger, it's still only 30 hertz, and it's SUPER choppy when I do screen mirroring. Also I'm seeing actual rendering bugs.
I bought the TV because it was large, not because it was 4k. I've used MacBooks with 1080p TVs for years and generally like it.