New Senate Rules, page-9

One big point to consider is that as it only requires a maximum of 12 squares to be filled in there will be (I hope) more people filling in under the line

IMHO I believe that voting over the line does not comply with the electoral rules of voting in that if you vote above the line you are not voting but giving your right to vote to someone else and as you will never know who that vote goes to you will in effect not be actually voting.

IMHO there will be more "solid" independents and less "one thought" applicants, so both major parties will lose senate seats

Fill in under the line with 12 numbers and do it with a pen