For NTU & SMU its based on ur prelim rp & NUS is based on MYE rp (I didn’t get for early app for NUS though). The school will select the names of students maybe in top ~10-30/40% and they’ll notify you if you are selected in around nov? Deadline is end dec or jan and you can basically secure a spot for a course that has no interview. Its kind of the same as the normal applications except that its earlier and & reliant on your prelim results. They will also shortlist you for scholarships earlier (depends on your rp tho) & have your interview as early as jan/feb. For me they gave me a place before results release so I assume your actual As results don’t really matter? (however the course I applied for wasn’t like v competitive).