I wouldn't recommend it, it's important absolutely get everything correct in Further to get a high score in it since everyone finds it so easy. People often think it's much easier and would be less work, which is where they go wrong. This is because to actually do well, you need to practice over and over, until you spend about the same time as other subjects. If you don't, you'll lose small marks in the exam/sacs that would have a huge effect on your study score. You have to be at the very top since it gets scaled down, and I know a whole bunch of people who dropped from Specialist 1/2 to Further in my school, and they are bloody smart and spend 5 hours a day studying on weekdays. These are the type of people you're going to have to beat, if you think you can, be my guest
If you've already done Methods 1/2, just continue to 3/4. Even if you didn't do too well in it last year, about 70% of the course is the same, so you can just relearn it. Plus, you get a nice scaling up even if you get middle band. You don't want to be regretting taking the easier subject at the end of the year