Personally, once the Championship is launched fully (and based off the whole 'Group Stage' numbers, I'm expecting that to get to 16 - it should go to a 64 national stage:
14 A-League clubs (assuming Canberra comes in eventually)
16 Championship clubs
Then, that would have 34 Member Fed clubs - based off the current breakdown, would probably be something like:
- Capital Football - 2
- NSW - 6
- Northern NSW - 4
- Northern Territory 1
- Queensland - 6
- South Australia - 3
- Tasmania - 2
- Victoria - 6
- West Australia - 4
Alternate option is to have the A-League all enter at the Round of 32, but having a national stage for the previous round including the Championship (again, will use 16 as the template), which would instead mean a 'Round of 50'.
This essentially would mean the First Round Proper (with the 16 Championship clubs, plus 20 Member Fed clubs (1 less than there is currently), and then the 18 winners advancing to the Second Round Proper (which would now have 32 clubs remaining).
If there's 14 clubs in both the A-League and Championship, this 20 Member Fed clubs would instead be 22 (meaning we'd need to allocate one extra to the current slots - and a First Round Proper (which would still be a "Round of 50")