(click to show fullsize)

Cage's script works best when transferring morphs from a highrez to an identically shaped lorez mesh.
As I almost exclusively use V3RR and many custom morphs are avaliable for standard V3 only, this allone is a great help.
It also allowed me to create a fully functional lorez MIKI as well as lorez versions of Laura, Maddie, ...etc.

But the script also works between completely unrelated meshes, even if there are a few caveats.

Transferring V3's head shape over to V4 doesn't work.
Same with transferring V3's bodymorphs over to "V4toV3".
(I really hoped that would work because V3 and V4toV3 have identical shapes)

But transferring V4's expression morphs over to V3RR worked quite nicely as you can see on the attached picture.
A bit of cleaning up is necessary for open mouth morphs, but this is far easier than creating expression morphs completely from scratch.

I had to create a "dummy V4" cr2 that places V4's head as close as possible over V3RR's head to line up the mouth and nose and eyes.

Of course the closer both meshes are, the better the result will be.
For example I was able to transfer those V4 expressions from V3RR over to V2LO with no further modifications necessary.