One of the mods that can be done is adding 1440p 14" ips display, like the LP140QH1-SPB1 from the carbon x1 gen 2. It's not as good as a new macbook pro display, but it's very nice to use.
Note that ThinkPads’ display quality always had been far behind competitors across the industry, at times of launch of each models, not against future laptops.