I believe the points stay on your licence for 5 years but now you only have to serve 50% of the time and you will be let off.
The points are valid for 3 years, they remain on the licence information for 4 years, you must declare them to your insurance company for 5 years
Regarding the % that the different police forces allow, this is only a guideline, not law If say, Nottinghamshire allow 10% +2, Leicestershire could allow 10% +3, then there is North Wales, they allow 1 or 2mph, they are very strict, they don't give the 10% part of the guideline
I suppose that she might be fairly hostile if she has a Dragon Bank Card! And I think you might be on to a winning business idea- A Dragon Bank payment card?
I suspect they don't from my own experience having attended 3 of the various versions. Only the seatbelt course and motorway awareness changed my behaviour. The speeding course didn't as less than 12 months later I got myself 3 points on my licence which has now modified my driving. I drive over a 1,000 miles every week sometimes more not often less. Being in a van means certain roads have lesser limits. I as much as possible use cruise control or speed limiter and always drive with Google maps to warn me of cameras. You posted later you were 81 in a 70, was that in your campervan?
This offence was in the Audi Q3, the Campervan IIRC was 71 in a 60 I’m guessing in 2015 on the Ilminster bypass, which is not a dual carriageway.
You're correct it's not the law, but I couldn't find any evidence saying any county/force doesn't stick to their own guidelines. Here's the doc: https://library.college.police.uk/docs/NPCC/Speed-enforcement-disposal-guidance-2025.pdf And a snippet (page 6) of the limits, and whether you'll get as course or a fine:
