max8 has an new feature for uv mapping.
in max tutorial,
Search "
Mapping the Pants" for tutorial.
it gets a rich content about uv mapping.
in max user references,
Search "
Pelt controls" for details.
this function can help your aims in your model.
it is similar with your expected method.
Note for you:
Pelt controls
These tools, which give you different ways of specifying pelt seams,
are available at all sub-object levels of the modifier.
Point To Point Seam
Lets you specify pelt seams by selecting vertices with the mouse in the viewports.
Pelt seams specified with this tool are always added to the current seam selection.
In this mode, after you click a vertex,
a rubber-band line extends from the vertex you clicked to the mouse cursor.
Click a different vertex to create a pelt seam,
and then continue clicking vertices to create a seam from each vertex to the previous one.
To start at a different point in this mode,
right-click, and then click a different vertex.
To stop drawing seams, click the button again to turn it off.
hope this help