I manually set UI scaling in Factorio to 150% when playing on a 4K monitor, which is also the default for Windows.
200% makes the UI elements a bit too large.

I don't know why Factorio defaults to 200% on the same monitor, maybe it's assuming people are playing on a TV across the room?

Turns out it's possible to escape the lava by rebuilding an elevated rail and train (or just a cargo wagon in this case with that's in the inventory).
It still seems wrong, though, that falling in lava doesn't harm the character.

While riding an elevated train on Vulcanus, my rail support was destroyed by a Small Demolisher. The track and train are destroyed, as you'd expect, and the player falls into the lava. All as you'd expect. The player is then simply stuck in the lava unable to move, but not taking any damage. The ...