Hello.
Though I agree that is a wonderful idea for diversity of different maps, I believe it wouldn't be used enough to include into ULX as a standard feature.
That being said, a module could be written somewhat easily that would allow the action you're aiming for.
I currently do not have the desire to code such an addon, and most of my teammates don't have the time.
Perhaps you know some Lua? Perhaps it's time to learn?
Perhaps someone else around here likes the idea also and could tinker?
The Gmod wiki has several entity commands that could be reviewed as a basis.
See Entity:GetPos. If I were researching, I'd also recommend looking into the ULX code to see how it's jail and teleport work.
(Teleport because it deals with vectors, and GetPos returns a vector)