Hi Steven,
I bought a Samsung 34" Wide Screen Thunderbolt3 Curved Monitor for my Sureface2 Laptop (Surface Laptop 2 Model 1769 i7).
Reading your above post I should have no problem outputting to this single screen at the required resolution 3440 x 1440.
Sadly using the Surface Mini Display Port and having purchased several Amazon adaptors (mini to HDMI) latest being the CableDecom HDMI 4K X 2K I'm stuck with a disappointing 1920 x 1080. I read about active HDMI cables and and adaptors (I thought the CableDecom was) however, before I spend more money I'd like to understand if I'm barking up the wrong tree and there is something more fundamental here i.e. you need to use a Dock Station for example or something simple I've not done!
I have a ThinkPad X390, that was plug and play with the Samsung via its built in HDMI port i.e. the Samsung is working fine.
Appreciate your support
Cheers
Andrew