Arguments about the value of setting aside...
I cannot emphasise enough how little what set you are in means at all. The only context in which it really matters is whether you do the foundation or higher tier papers. If you're aiming to do higher tier and your set is being entered for the higher tier paper it doesn't matter if you're in the top set or the n+1 set above foundation tier, you're still doing the correct exam and you still have your own brain to actually study the material with.
Which set I was in has literally never once in my entire life made a single difference in anything.
In fact I would really like to know what the logic behind the claim that which set you are in could "ruin your future" at all?