I think tail vices aren't that common over this side of the pond from what I can tell.
It looks like a neat idea. I use wedges quite often to hold stuff, a bit like this:
but I've got loads of dog holes in my bench so I can usually get away with a small off-cut to make up the gap if required.
I made a thing I called a "
dog hole tail vice" for the occasions I really want to clamp something up against a planing stop, but 99% of the time I just use a doe's foot, which is plenty strong enough for most planing jobs. These are the first couple of photos I found of the doe's foot
That second one is very old: I've got more planing stops now and the vice fixed jaw is flush with the front of the bench. Oh, and the bench has a lot more dents in it!