I checked with Oz Linden about the Mesh Deformer Test Garments in Hippo Hollow. I wanted him to remove the old garments that do not work with the current deformer. He prefers not to, being concerned it might signal some action on the Deformer. I disagree and think non-working garments are creating more confusion, just read the 1716 JIRA thread. But, it is his choice.
I think this signals a full stop in the Deformer. Oz is taking every opportunity to request more staff and get the project moving. But, it seems the project the Lab saw as low priority remains low priority.
If you want to test the Deformer, there is a dynamic link to the latest version of the Project Viewer, which was updated this week. Code from the other viewer development branches were merged into the Deformer branch. So, the Deformer Project Viewer is very much up to date. As far as I know there were no changes to the actual Deformer part of the viewer.
You will need to upload your own rigged mesh clothes and enable the Deformer aspect of them.