Hi there,
I tried it on a mountain bike with riser bars, but I found I couldn't really get comfy.
The reason I believe would be due to the top tube length, which I think would have been too long for comfort.
If you wanted a really upright position, you could try riser bars on a short top tube frame and add the aero bars for an aero option when needed. I wouldn't guarantee your comfort though.
Hope that helps?
Steve