Sykar
Arcane
Or just get the Sprint feat and Interloper feat for faster stealth travel.
Sprint is cool tech, but it doesn't help when you have to slog through cities, the cd is too long. Suggesting Interloper is just missing the point entirely.
Underrail really is not that big so I do not get this obsession with higher movement speed. I do not mind it one way or the other but you are turning a mole hill into a mountain.
Core City has muggers in certain areas which you can easily avoid with Interloper and decent stealth. Same goes for a couple of areas which spawn Siphoners from water for example so going through these via stealth is utlimately faster. If you opt for high stealth as a means to avoid combat then Interloper makes things a lot easier and you can quickly and safely go through many maps without any danger of getting discored, because regardless how strong you are even sneaking through with Interloper will be faster than any combat, especially on Autistic difficulty. So no it does not miss the point entirely.