HI Charles,
I think that the Curve Deform is the best option in this case, but, you need to do everything correctly. For instance:
If you need to adjust the size of the Curve, Scale it in Edit Mode, Do not Scale the Curve in Object Mode and then Apply the Scale! In fact, do all your Curve Edits in Edit Mode.
So, take your Edge Loop, P > Separate > By Selection. Object > Convert > Curve. Add Curve Deform to your controlbox.
There might be an issue with mismatched Origins: you want both Origins in the same place,. So what you can do, is Select the Curve and CTRL+A > Location and CTRL+A > Rotation. Then Select the Controlbox and (maybe Set Origin to Geometry, depending on where its Origin is and then) ALT+G.
Switch the Curve to Edit Mode and do whatever Transforms you need to do.
The Simple Deform is great in a lot of situations, but here you have indeed the problem of getting the Angle right, to fit the Cylinder.
There might also be situations (depends on how things are modeled), where you can use the new (5.0) Array Modifier to your advantage.
