Last year I removed my non-working light. I don't remember the remaining one being tested, but I thought if they were there they're supposed to work. I've currently got four additional lights out (two fog, two DRL) so am thinking of removing them in advance of the MOT at the end of the month.
I'm also thinking of better ones than the cheap Chinese fog lights as they don't last & while they're cheap enough to replace, replacing them is a PITA as I've soldered them all up.