a 61.75 is issued by the FAA without a BFR
no knowledge of FAR s is required to obtain a 61.75 and if you never fly in USA you will never need to know any knowledge of FAR s
however to pass a BFR you will certainly need knowledge of the FAR s especially airspace classification and air law as this is asked on most BFR s when the cfi asks questions
strange isn't it ambiguities like this normally comes from the UK caa not the FAA