Most people are paranoid about breaking the glass (w/o defrost E0TZ9842006B, w/defrost F2TZ9842006A) if it's fully extended with the t/g down, but I do it all the time, and I've never broken one. I even use it as a VERY-LIGHT-DUTY work table. I don't jump on it, but that 12V impact weighs a few pounds, and it's fine.
If your t/g is already split along the R side, don't do this. It won't hurt the glass, but it will do more damage to the t/g skin. For more info, see the
Right Side Split album..
.
