ACZoom

I exactly encountered the same issue and more or less did the same steps, except that I found issues around resizing the root partition file system afterwards. It just didn't do it. Also when I though more about it, I think, even though there could be various ways to achieve this nested lvm in guests, we lose all the flexibility that the raw partitions/file-systems tools provide. Currently most of the tools can't manipulate the lvm volumes as they can e.g. other file system type like ext3.
I was able to see the 'inside' partitions from the fdisk/parted including lvm volumes but the host lvm itself couldn't manage the nested volumes. So unless lvm tools are able to do it, such operations are indeed dangerous!