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?
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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)