I think you will find that the 30 days is a min and you must get/bid for that much or they will allocate leave at this early stage and not ait for the matrix in the manual to kick in.
I also think that the 30 days is our "official "leave and the other 12 are for the public hols.
I got 21 peak (second Choice) and 11 non-peak (first choice) and the system shows 10 still avail. Will be interesting to see what happens in Jan.