As far as Im aware, I AM getting all of my FTB (A and B) fortnightly and the difference is corrected at the end of financial year depending on my OH salary. I thought that is what I nominated when I applied. But maybe I misinterpreted/ forgot/ that has changed since then.
If Im not, then you're right, it wont make much difference to me and I have nothing to worry about. (Except that we use the reconcilliation at the eofy to pay car rego/ other big things that we struggle to manage throughout the year)

If you receive full ftba supplement its a rate of 1.99 per day per child that you cannot physically receive during the year. So just short of $30 a fortnight you CANNOT choose to receive until after your tax is finalised. It's a daily rate. The same as every other payment.

Eta. You are most likely receiving all the entitlement you can on a fortnight basis. This is part of the ftb you cannot get fortnightly