I did a lot of research into this when I had my 120. The safety factor checks out, I used some applet from our homepage. The actual experience from others is that the glass bows. For that reason, I looked into euro bracing. IMO, that looked like the best option. Having never done it though, I can only have an educated guess as to the outcome. I did talk with Will at Premier about this, he recommended a brace of some sort. He makes metal braces, didn't have any that would fit a 120 when I asked though, just a 125.
You can try it if you'd like, I'll even help you move it
Edit:
found this guy. Safety factor must be 7.8 for rimless, they say.