When AADSAS verifies your GPA, you will notice that they calculate your GPA without +/- and with +/-. This will be available for adcoms to see and they will make their decisions based on one set or both sets of data.
Oh Boy! Another thread on GPA and this one is more detail
In my GPA calculation there is only .106 diff between +/- and fixed letters. Whatever + you have is counterbalanced by -, so there is not really any diff.
Why AADSAS calculates both is because some schools prefer with +/- and some don't care and take the raw letters.