ucs in paper space and model space

Are you talking about the orientation, or the panning, or the scale?
The panning is easily done, while in a layout in model space, select a viewport, pan & zoom till you're happy, then change to paperspace.
In model space, and in each viewport in a layout (while in model) there is a UCS setting "Update view to PLAN when UCS is changes".
When this is checked in model space, when you change to a new UCS orientation it zooms out to the max, and re-orients the view to the new UCS.
In a layout, it will do the same to a viewport when you switch to model in a layout. Once you are satisfied with the viewport, switch back to paper, and you can right click on the viewport border, and choose it's "locked" property so it doesn't keep changing.
GC

The UCS in a port is subject to change. Provided that you don't pan or zoom in the port, if you could place, say, a corner of the viewport contents at the origin in MS, you could then move the port corner to the origin in PS.
What purpose all this might serve is not apparent to me, however. I don't understand what "spacing views" means.

I could see how the origin might be useful if you were dimensioning, but why would you ever want to swap the plane in PS?