I can't see the attraction of a combined isolator, fuse and light switch. The only thing I want 1200mm off the floor inside the door of my bathroom are the switches I'm likely to need when I use the room for one or more of its intended purposes. These are typically a two or three switches for lights, possibly a separate switch for an extractor fan (with neon), if the room has an opening window, and maybe switches for a towel rail and UFH.
The isolator for the fan, and for anything else that needs an isolator can go high up outside the door, where they don't detract from the decor of the bathroom.
My own preference for a fan isolator/fuse, is to use a DP isolator and fuse, and feed the main light of the bathroom through it, as well as the fan, to discourage people (especially tenants), from turning the fan off and leaving it off.