If the deformer did not work for you, maybe the problem is not the deformer, it's the mesh you made. As you can clearly see in Medhue's video the deformer works exactly as expected. I had the same results as Medhue. It worked fine for me. I did tests of making mesh that had a vertce layout different from the avatar and making clothes that were cut from the avatar. The clothing cut from the avatar always worked better because it is the exact vertice layout of the avatar. As long as I made sure the vertice layout mimicked the avatar in certain problem areas I had good results. Lets lay this out plain and simple. The avatar DEFORMS to make different shapes. When you use the shape sliders the avatar is DEFORMING. The "Deformer" works on the same formula as the avatar and will work exactly how the avatar does. The mesh that is deforming along with the avatar will go short, tall, fat, skinny, pregnant, LARGE breasts, small breasts, big butt etc ect ect. Because the avatar will deform to all those shapes. Give us BOTH! Let the creator make the choice on how they want to work with their mesh and creations, whether they want to use the deformer or collision bones. It's like forcing me to use Maya rather than Blender or visa versa. We all have our own preferences and work flow. LET US USE WHAT WE WANT! If you want to use collision bones, more power to you, create until your little hearts content, but don't refuse me the same respect. I helped pay for the deformer to be developed as did many residents. IT WORKS!
My only guess on why the Deformer was never implemented was purely political by LL, and if someone other than Qarl had developed the deformer, it would have been implemented a year ago.
Direct quote from the blog.
"Neither approach completely eliminates the occasional need for an alpha clothing layer to prevent small parts of the avatar skin from appearing through garments, but both work quite well at resizing garments so that they fit the avatar and move naturally with it."
Both work quite well.
Goodnight.