I'm a fuse tugger
I didn't want the uncertainty of losing a washer - and yes, I do use a high concentration of fan jet washer fluid.
Two minutes to pull a fuse out gives me peace of mind that my washers will remain intact. If I want, I can pop the fuse back in, and these days I don't do enough long night journeys to worry about reduced light output.
Nobody has ever accused me of being sensible though.
Each model e9x is different so if you want to pull the fuse, you HAVE to look on the card next to the glove box fuse box.
MOT's - there are lots of anomalies. We see chavtastic cars with HID headlights. These are technically illegal and should not pass an MOT, but they obviously do in places. Likewise, if Xenon's are fitted, they MUST have self adjustment, either on the car's suspension (like fitted to the E61), or on the lights themselves. They MUST have washers too, and of course, they should work. I would suspect that most MOT testers wouldn't bother testing the headlight washers, if only to stop half a gallon of water pooling where they want to work each time!
Mike