Don't be completely discouraged by the downside.  There could be
a useful idea somewhere in the vicinity, even if the original
thought doesn't quite do it.

I doubt that it would help much on welding two pieces together.
Usually that means building a "bridge" between them.  In some
cases the modeling app can make such a bridge automatically;
in other cases it requires hand-drawn facets or adjusting or dividing
one of the pieces.   But those processes have to be done directly 
on the vertices themselves, so the UV map wouldn't
add useful information.

= = = = =

The pink and blue thingies have the same grid pattern, and when
seen from above (in a flat non-perspective view) they look just the
same.  So when UVmapper does a planar map on the Y-axis,
it creates exactly the same picture.   The thingies could even have
lots of bumps and dips, and they'd still have the same map
as long as the mesh was morphed vertically.  

My python page
My ShareCG freebies