Matt,
That is not consistent with my understanding.

Are you sure that you are not comparing the masts
used by AHPC on the T4.9 and T5.7. because the T4.9
would fit inside the T5.7 mast if the track was cut off.
Also the original Aussie wing (extruded to avoid importing Sori wing mast from Italy for A class) would fit inside the T4.9 mast.
A quick measurement of the major and minor axis would
tell the story.

Regards,
Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!