I've been pondering a similar thing (albeit I had been looking at the SoaringXX model (SoaringXX Tow out bar Giga)) Both look fairly similar from what I can gather.
Sadly, I'm not going to be near the glider for a while to take some measurements and try drawing it up. I'd love it to work so I could change out the tow bar I'm using as well. My suspicion is that with the dolly on the tail and then raising it up further on the tow bar support plus the extra height of the tow bar having wheels itself could be a bit high.
That said, the image below from the IMI website and shows an is an ASW 15 with one of their light towbars attached. Seems pretty well lifted up at the back end! Would suggest to me it should be possible.
.jpg)