Hopefully that will be a nav update as I've got a good test run tomorrow that will show if they have updated some out of date speed limits.
Was able to give the latest EU-2021.8-12875 nav update a bit of a test. A mixed bag of results.
A319, Chobham to Ottershaw past Fairoaks, it now knows that this is a 50 - previously it was NSL. Ordinarily this road would be covered by visual speed limit detection, but as I recently discussed, there are a couple of places where it incorrectly picks up the speed limit from a side road which when the car realises that it has passed will briefly use the default map until it next picks up a visual road sign. This brief limit is now correct at 50.
M25 clockwise/M3 south intersection. This merge is a 50 for quite some distance. The car briefly picked up a 50, I think rather oddly from a lit speed limit indicator. It unfortunately then incorrectly reverted to 70 and remained. This merge has been a 50 for many years now and covered by average speed check.
A331 BVR from M3 J4 heading towards A31 Hogs Back. The initial few miles of this route was changed from national to 50 a few years back. It is also a NoA section. Even though that section of road is littered with 50 signs and repeaters they were completely invisible to the car. Previously this section of road was detected at NSL/70. Heading away from M3, the section of road is now correctly detected as 50. Again, visual speed limits are invisible. Returning towards M3 from NSL/70 back into the 50, the 50 is now correctly detected but not until well past the sign. TACC/AP speed limit remained on 70 so even if your car did slow for speed limit changes (ours doesn't - tested today on AP/NoA), based on behaviour seen, the car would remain exceeding the speed limit.
One final observation, for todays return journey, the car wanted to take me a completely different route than normal (it normally routes me via a shorter set of A roads rather than as today, a longer motorway route). Now, this may just have been traffic, but not really any different than normal, or it could be something else. I am doubtful of the nav update having any bearing as, my understanding is that routing is done off line so not dependent on my cars map. But its mightily coincidental. As we now have a long section of A road now reduced from 60 to 50, that may be enough to swing the time - I have actually done several 'race' in two cars simultaneously taking both routes and in real life, there is literally nothing in it with both cars pulling up pretty much within a few tens of seconds of each other.