AutoCAD Civil 3D :: Roundabout Approach Leg Modifications

I am using the roundabout design tool as the first step in developing the 2D design of a roundabout. I am having some trouble getting the defection path radii I need in order for the roundabout design to progress to the next step, however this can only be achieved if I can alter the alignment of the approach legs.

The default setting for the roundabout tool/wizard is for all alignment legs to intersect at the centre point of the roundabout - something which does not readily allow the deflection radii to be met even remotely (in this case and others)

Whenever I try and realign the alignment/approach leg and run the design wizard again (in the hope the other kerb alignments will realign to match), it jumps back to the initial alignment pointing to the centre point. Refer attached screen shots.

Of course designing the roundabout in the traditional way is always the sensible alternative to achieve the correct layout & deflection, however if this function exists it would be handy to speed up the initial design process.