Uh, just where on a pair of
Crank Brother Egg Beaters are reflectors going to be attached? I suppose that they could make the small bit in front and behind where the cleats clip in reflective but that's about it.
You may/will find that somewhere in the small print on the packaging/instructions for a lot of pedals, the manufacturers state something along the lines of "not for road use" or "track use only" to cover themselves if the buyer gets nicked for using pedals with no reflectors on the road.
Once again, legistlation fails to keep up with technology, as you have to have correct, approved orange reflectors which, as you so rightly point out, would be a tad difficult to fit onto many SPD/SPD-SL pedals, whereas a suitably-sized strip of Scotchbrite tape would do the job equally well without the bulk.
Anyway, knowing the UK and it's carefully-worded laws the pedal reflectors, as with the bell and rear reflector, are probably only required 'at point of sale'.