I have the ultra. For larger projects (larger bits or bigger vertical
pieces), I built an auxiliary fence from melamine that has a short
side that clamps to the ultra, and a tall side about 8" away that I
work off. Since it has a wide footprint, it holds itself vertical
under heavier load.
I have had no problems with the fence moving around once it's locked
in place, but you can always clamp the fence to your table if needed.
Do you have any specific questions about it?