@MYOS1634 You’re assuming that all GCSE courses are accessible to students when at many sixth form colleges or certain schools sometimes only offer 6-8 GCSEs. I don’t think you should worry about GCSEs if you have 3 A* prediction at A level. If it’s that worrying then individual can add a little diversity in their A level subject choice or take additional AS level subjects or sat subject tests.
APs are weaker than A levels. Someone who can get 3 A* to 4 A* in their A levels is within the top 2% of students in the UK. If someone takes 4 A levels and an AS level and gets 4A* and one A in AS then they are in the top 1% of students. that’s the type of student that could be successful applying to MIT or when applying to Ivies.
@Donthatejust There are many top test flexible universities in the us I’m applying to one myself although I would choose to submit my test scores.
Here’s a link showing the complete list of test flexible/optional universities:
http://www.fairtest.org/university/optional