Hi Paul,
I am glad you can pass your annual MOT tests despite your mods.
Here is a good summary of the legal implications in the UK, but you probably know that already:
https://www.autobulbsdirect.co.uk/blog/are-led-headlights-legal-in-the-uk/I did not include all the arguments that Stern provided especially about the beam pattern being the same because it really gets deep into optics and visual perception. Looking at the beam pattern on a wall and comparing it with the previous one stored in your brain's memory is a tricky one. During your annual MOT does the tech use a beamsetter, or is it all visual?
Even with a headlight adjustment device (beamsetter) the Mercedes instructions in the BBB (
https://www.sl113.org/wiki/Electrical/EuropeanLamp) indicate that the light/dark break is not always clearly visible.
Stern points out that taking photographs of beam patterns and comparing them is also fraud with problems.
"Fact is, photographs of beam patterns are very misleading even if the photographer has the best of intent and purest of motives. That's because pixels and film work in a fundamentally different way than human eyes. Even a photographer who diligently tries very hard to keep all the camera settings identical when photographing different beams up against a wall cannot present more than rough general information about the beams, and then only by comparison (a sharper cutoff vs. a fuzzier one, for example, or a wider beam vs. a narrower one).
In short: a very good, very carefully made photo of a beam pattern can potentially tell a trained, knowledgeable individual how bad the beam is, but not how good it is, and even the best photo of a beam pattern can only mislead someone without the training and knowledge."
Of course, if you are pleased with the results then leave it that way .... and try to never drive in fog when the low beam pattern is especially important.
However, if you want to dig deeper into this field then I recommend to look at the information that the Lighting Research Center at Rensselaer provides:
https://www.lrc.rpi.edu/programs/transportation/index.aspEven more fun is to drive a car by night on a winding road that is equipped with "Adaptive Driving Beam" technology. On my last visit in Germany I drove an E-class equipped with this system and it was amazing. Unfortunately, here in the USA we are still in the dark ages and have to wait until the NHTSA gets its act together.
https://www.youtube.com/watch?v=xYSix5r38qYDrive safely and stay well.