My english wheel was not great new out of the box. A lot of deflection. So i welded a round of 2x2 square tube and embiggened the corner braces. Now its rigid.
I cut a piece of 4” plate 12”wide,slot down the length to match the bead roller. Spacers and bolts to take the flex out of it. It wont be a problem with heavier stuff now.
Complex bends/curves?
Cover area in duct tape-2 layers.
Peel tape and cut slits so it will lay flat on your sheet metal.gives you a great template. As you work it and weld slits back together it gets your panel very close. Done it a few times, works well.bigger flat areas i use heavy paper and duct tape the same way. Drawing lines to represent bends.