Your need to ask their admissions team this question as only they will be able to give you a definitive answers.
A FY does not replace the entry requirements needed so they may say that you will not be able to transfer due to this and that's why as good as FY's are for access to university, you are more locked in. However, it's always worth asking the question and when transferring you need to ensure the modules of both courses match up as best you can as this is what they will look at as well before considering a transfer directly into second year.