You'd have to ask your curriculum co-ordinator, most probably. As long as you're taking advanced english and are confident, i see no reason why there isn't enough time to add an extension. In my english extension class we really haven't done much. (especially considering how many lessons a cycle...
I always thought that was impossible because the sor 1 course and sor 2 courses are too similar. (because sor 1 and sor 2 do the same studies, but sor 2 covers content which the sor 1 course doesn't) and also because they're usually on the same line? :S
So far, we haven't really learnt much that we can put down as 'notes', so i haven't done most of my subjects. I've started notes on economics and modern history though