Spider, the solution I have come up with is to use the "user flange"
Produce your main wall as normal.
Produce a Sketch of your tubed flange.
Pick this as your profile
Use the wall edge as the Spine (this edge is the one where the tubed flange is attached)
Pick the two limits ie the longitudinal wall edge + a plane designating the extremity
And hit OK.

Flange can be flattened as you require