But anyway, are fog lights really that dazzling?
Yes, now turn them the f*ck off unless it's REALLY foggy.
It's not just brightness. It's the focus/spread of the beams. Get your motor down to VOSA and get it assessed if you're worried. That way, if it passes and a copper pulls you over, you can wave your certificate in their faces.
Do they hand out individual certificates then?

With lighting it's normally E-Marked for the application, which is why mucking about with it in any way means you're out of type approval and out of being legal. This may be the biggest issue with Rhys's use of the lights, unless they're used as DRLs in later Aldis.