I wasn't giving advice on just what to do RIGHT NOW, but moreso how you should approach Y11 with a mix of 1/2 and 3/4 subjects. I agree, 3/4 subjects will feel more important because they count. But let me draw out a situation.
Let's say I am doing these subjects (for simplicity sake, let's say I'm only doing 4 subjects):
English 1/2
Methods 1/2
Chemistry 1/2
Physics 3/4
I spend a lot of time on Physics 3/4 and hence, I end up getting a 50, whilst my foundations are pretty shabby on the other three subjects. I end up getting 36, 38 and 41 on my other three subjects the following year and as a result, am disappointed with how I went in Year 12.
I'm given a chance to go back and redo things. This time, I focus more evenly on all my subjects and hence, I only score 45 in Physics. However, I have identified that English is my weak point and have worked on that throughout Y11, thus, leading me to get 40 in English. I also go in with a better foundation in Methods, getting a 41 and having a better understanding of bonding, gases, redox reactions and stoich in chemistry, thus, getting a 43.
Well guess what, I manage to get a higher aggregate - so lesson/moral - Y11 subjects are important, don't neglect 5 subjects for the sake of 1.
by this point you would already have a solid foundation as you have worked consistently throughout the year and done the work. You are not missing out on gaining knowledge or learning concepts that will be revisited in year 12.
I disagree, pre-exam study - you learn a lot.