Special consideration for gcses

Hey! So for my gcses I've applied for special consideration and idk how some of it works so it's likely I'll get around 2% for my extra marks but is this applied for each paper or for the total of all the papers I've done for that subject eg say maths will this be applied to each paper or the combined marks for all three of the papers (if that makes any sense) and could I get a different percentage for each exam board or could one of them decline my special consideration request. Also, when will I find out if I've gotten it or not because I think it's my deputy head is going to apply for it for me so...