I cannot recall anything in the regs to suggest other wise . Although I am always a little dubious about running the neutral in a connector inside the switch box . I wonder if perhaps a manufacturer could create a 5amp plate switch with a neutral link specifically for the the purpose of wiring behind a switch?
Not haveing a go but why not a connector block in a switch box? I would normally 3-plate at a ceiling rose but if you are running away to say some wall lights, they are buggers for no space. Makes sense to keep connections to a minimum. Or are you suggesting through crimps.