My impression was that it can capture road elevation, but most OSM contributors don't. I know it supports capturing the elevation for specific points (as well as the heights of things like buildings), and I'm pretty sure OSM includes terrain elevation as well.

Well, it'd make a for a good starting point for a developer - they could then mangle, simplify and merge Ordnance Survey (UK) or national equivalent elevation data..

..and then, like with the bots that supposedly roamed No Man's Sky's development, ensuring no random variables came out with anything rude or inappopriate, make bots like that here to check the merged output isn't quirking too much :)