I've found ideal monitor size and resolution depends greatly on viewing distance and relative position. I use a 38" ultra-wide and it's almost too wide - but I have it 'floating' on an adjustable monitor arm so it's only about 24" from my eyes and a bit higher than most monitor stands would allow. The monitor arm is key because once I put a full ergo split keyboard at a comfortable arm-rest distance, a normal monitor stand sitting on the desk would force the monitor to be too far back.

For the full breadth of a 52" monitor to be comfortably viewable for detail work, I'd have to be farther back enough that the difference between 4K and 6K wouldn't be meaningful. It's kind of like how 8k resolution can provide meaningful value in a head-mounted display two inches from your eyeballs, but 8k on a 65" living room TV seven feet away from your couch viewing position is pointless because even those with 20/10 vision can't resolve the additional detail at that distance.

For detail work I find my best ergo seating position is up close with my legs tucked well-under the desk and my stomach almost touching the edge of the curved desk inset. This allows my forearms to be supported comfortably on the desk. I also have my desk surface a little lower than most and my Aeron chair a little higher, putting the top of my legs almost touching the underside of the desktop.