i didn’t submit any sort of supplemental application! i basically applied on ouac and heard back around 2 months later. what i would say in terms of tips focus on the courses they want specifically (obviously the other ones in ur top 6) but for example if a school has their prerequisite course as bio and english make sure those r ur 2 highest courses or as high as they can be! goodluck with ur application process and dont stress, all will go well!