Even if the RAAF don't charge or AsA don't charge on their behalf, I wouldn't have thought the charges for 30 nm of airspace would be too high.
Some of the smaller operators using singles would only be in RAAF aierspace at the moment until the CTR boundary, hence the extra charges would be negligible. 13nm
Now the savings made by the more efficient operation would out way the possible negatives anyway.
I think most operators would certainly prefer and be better off with Asa.
Just my oppinion.