The last thing we would recommend is shortening the A-frame.
The minimum articulation published in the Government Gazette No. 97 of 5 February 2010 specifies a clearance space of 1 metre from the centre of the towball to a position that is 30 degrees from a line drawn from the centre of the A frame to the front of the caravan (see the diagram).
Any modification of this nature will void the manufacturer’s warranty, and may not be acceptable to the insurance company should you ever have an accident.
Also, there is the relocation of the axle, which may possibly weaken the chassis if you are drilling more mounting holes, and also make it necessary to reset the Skipper’s brakes.
May we suggest that you get Skipper to do this modification so that you still have all the warranties in place?