[lghh]

I have a LG 38WN95C (3480x1600, 144hz, thunderbolt 3) monitor that's plugged into my Macbook Pro (M1 Pro _I think_, I'm not home to doulble check). The laptop is in clamshell and plugged in via Thunderbolt 3. IIRC, I had to turn the refresh rate down to 120hz, but otherwise it works well. The only hiccup is that if I unplug it, use it for a bit, and plug it back in I have to open the lid one time after plugging it in so it can realize it's plugged in to a display.

I have a M3 Pro MacBook Pro for work that I also swap between on the display using the single cable that I remove from one to plug into the other. The laptop travels with me to work where it plugs into a 16:9 4k 60hz monitor while it's open. I have the same clamshell issue as my personal laptop where I have to open it once after plugging it in, but otherwise it works pretty well.

I do however have to do some workspace rearranging when I go from clamshell->ultrawide to my work setup of open lid->16:9 monitor. But that's no a huge deal since I'm going from 1 screen to 2 screens.