In that thread that was recently taken down, one of the side discussions was about whether Wing Chun contained standing grappling elements and whether Chi Sau was inherently a training method for standing grappling in addition to other things. Here is at least one lineage that thinks so! Recent clip from Alan Orr. Notice how he goes from Chi Sau to a standing grapple of some sort about as often as he goes from Chi Sau to striking. Note that the neck control he likes to use is right out of the dummy form.
Chi Sau "range' is a grappling range.
Chi Sau "range' is a grappling range.